Fused heterocyclic derivatives as S1P modulators

ABSTRACT

This invention relates to new fused heterocyclic derivatives having affinity to S1P receptors, a pharmaceutical composition containing said compounds, as well as the use of said compounds for the preparation of a medicament for treating, alleviating or preventing diseases and conditions in which any S1P receptor is involved or in which modulation of the endogenous S1P signaling system via any S1P receptor is involved.

This application is a national stage entry under 35 U.S.C. §371 ofPCT/EP2011/061586, filed Jul. 8, 2011, which claims priority of U.S.Provisional Application No. 61/446,541, filed Feb. 25, 2011, U.S.Provisional Application No. 61/362,784, filed Jul. 9, 2010, EuropeanPatent Application No. 11156007.4, filed Feb. 25, 2011, and EuropeanPatent Application No. 10169107.9, filed Jul. 9, 2010, the disclosuresof each of which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION

This invention relates to new fused heterocyclic derivatives havingaffinity to S1P receptors, a pharmaceutical composition containing saidcompounds, as well as the use of said compounds for the preparation of amedicament for treating, alleviating or preventing diseases andconditions in which any S1P receptor is involved or in which modulationof the endogenous S1P signaling system via any S1P receptor is involved.

BACKGROUND OF THE INVENTION

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid that mediatesa wide variety of cellular responses, such as proliferation,cytoskeletal organization and migration, adherence- and tight junctionassembly, and morphogenesis. S1P can bind with members of theendothelial cell differentiation gene family (EDG receptors) of plasmamembrane-localized G protein-coupled receptors. To date, five members ofthis family have been identified as S1P receptors in different celltypes, S1P1 (EDG-1), S1P2 (EDG-5), S1P3 (EDG-3), S1P4 (EDG-6) and S1P5(EDG-8). S1P can produce cytoskeletal re-arrangements in many cell typesto regulate immune cell trafficking, vascular homeostasis and cellcommunication in the central nervous system (CNS) and in peripheralorgan systems. It is known that S1P is secreted by vascular endotheliumand is present in blood at concentrations of 200-900 nanomolar and isbound by albumin and other plasma proteins. This provides both a stablereservoir in extracellular fluids and efficient delivery tohigh-affinity cell-surface receptors. S1P binds with low nanomolaraffinity to the five receptors S1P1-5. In addition, platelets alsocontain S1P and may be locally released to cause e.g. vasoconstriction.The receptor subtypes S1P1, S1P2 and S1P3 are widely expressed andrepresent dominant receptors in the cardiovascular system. Further, S1P1is also a receptor on lymphocytes. S1P4 receptors are almost exclusivelyin the haematopoietic and lymphoid system. S1P5 is primarily (though notexclusively) expressed in central nervous system. The expression of S1P5appears to be restricted to oligodendrocytes in mice, the myelinatingcells of the brain, while in rat and man expression at the level ofastrocytes and endothelial cells was found but not on oligodendrocytes.

S1P receptor modulators are compounds which signal as (ant)agonists atone or more S1P receptors. The present invention relates to modulatorsof the S1P5 receptor, in particular agonists, and preferably to agonistswith selectivity over S1P1 and/or S1P3 receptors, in view of unwantedcardiovascular and/or immunomodulatory effects. It has now been foundthat S1P5 agonists can be used in the treatment of cognitive disorders,in particular age-related cognitive decline.

Although research is ongoing to develop therapeutics that can be used totreat age related cognitive decline and dementia, this has not yetresulted in many successful candidates. Therefore, there is a need fornew therapeutics with the desired properties.

DESCRIPTION OF THE INVENTION

It has now been found that fused heterocyclic derivatives of the formula(I)

-   -   A fused heterocyclic derivative of the formula (I)

-   -   wherein    -   R1 is selected from        -   cyano,        -   (2-4C)alkenyl, (2-4C)alkynyl, (1-4C)alkyl, each optionally            substituted with CN or one or more fluoro atoms,        -   (3-6C)cycloalkyl, (4-6C)cycloalkenyl or a (8-10C)bicyclic            group, each optionally substituted with halogen or            (1-4C)alkyl optionally substituted with one or more fluoro            atoms,        -   phenyl, biphenyl, naphthyl, each optionally substituted with            one or more substituents independently selected from            halogen, cyano, (1-4C)alkyl optionally substituted with one            or more fluoro atoms, (1-4C)alkoxy optionally substituted            with one or more fluoro atoms, amino, dimethylamino, and            (3-6C)cycloalkyl optionally substituted with phenyl which            may be substituted with (1-4C)alkyl or halogen, and        -   phenyl substituted with phenoxy, benzyl, benzyloxy,            phenylethyl or monocyclic heterocycle, each optionally            substituted with (1-4C)alkyl,    -   Z is a linking group —W—(C_(n)-alkylene)-T- wherein        -   W is attached to R1 and selected from a bond, —O—, —CO—,            —S—, —SO—, —SO₂—, —NH—, —CH═CH—, —C(CF₃)═CH—, —C≡C—,            —CH₂—O—, —O—CO—, —CO—O—, —CO—NH—, —NH—CO— and            trans-cyclopropylene;        -   n is an integer from 0 to 10; and        -   T is attached to the phenylene/pyridyl moiety and selected            from a bond, —O—, —S—, —SO—, —SO₂—, —NH—, —CO—, —C═C—,            —C≡C—, and trans-cyclopropylene;    -   R2 is H or one or more substituents independently selected from        cyano, halogen, (1-4C)alkyl optionally substituted with one or        more halogen atoms, or (1-4C)alkoxy optionally substituted with        one or more halogen atoms;    -   ring structure A may contain one nitrogen atom;    -   X is selected from C or N; if X is C, R3 is selected from H and        (1-4C)alkyl, otherwise R3 is not present;    -   Y is selected from NH, O and S;    -   structure Q is a 5-, 6- or 7-membered cyclic amine; and    -   R4 is (1-4C)alkylene-R5 wherein one or more carbon atoms in the        alkylene group may independently be substituted with one or more        halogen atoms or with (CH₂)₂ to form a cyclopropyl moiety, or R4        is (3-6C)cycloalkylene-R5, —CH₂-(3-6C)cycloalkylene-R5,        (3-6C)cycloalkylene-CH₂—R5 or —CO—CH₂—R5, wherein R5 is —OH,        —PO₃H₂, —OPO₃H₂, —COOH, —COO(1-4C)alkyl or tetrazol-5-yl;        or a pharmaceutically acceptable salt, a solvate or hydrate        thereof or one or more N-oxides thereof display affinity for S1P        receptors. In particular, compounds of the invention show        selective affinity for the S1P5 receptor over the S1P1 and/or        S1P3 receptor(s).

In WO 2008/012010, some of the disclosed compounds have somewhatstructural similarity to the compounds of the present invention;however, they are described as histamine H3-receptor ligands.

The compounds of the invention are modulators of the S1P receptor, inparticular of the S1P5 receptor. More specifically, the compounds of theinvention are S1P5 receptor agonists. The compounds of the invention areuseful for treating, alleviating and preventing diseases and conditionsin which (any) SIP receptor(s)—in particular S1P5—is (are) involved orin which modulation of the endogenous S1P signaling system via any S1Preceptor is involved. In particular, the compounds of the presentinvention may be used to treat, alleviate or prevent CNS (centralnervous system) disorders, such as neurodegenerative disorders, inparticular—but not limited to—cognitive disorders (in particularage-related cognitive decline) and related conditions, Alzheimer'sdisease, (vascular) dementia, Nieman's Pick disease, and cognitivedeficits in schizophrenia, obsessive-compulsive behavior, majordepression and autism, multiple sclerosis, pain, etc. Preferably, thecompounds of the present invention may be used to treat, alleviate orprevent cognitive disorders (in particular age-related cognitivedecline) and related conditions.

In a preferred embodiment of the invention, the compounds have formula(I)

wherein

-   -   R1 is selected from        -   (3-6C)cycloalkyl or a (8-10C)bicyclic group optionally            substituted with halogen, (1-4C)alkyl, and        -   phenyl optionally substituted with one or more substituents            independently selected from halogen, cyano, (1-4C)alkyl,            (1-4C)alkoxy, trifluoromethyl and trifluoromethoxy;    -   W is selected from a bond, —O—, —CO—, —S—, —SO—, —SO₂—, —NH—,        —CH═CH—, —C≡C—, and trans-cyclopropylene; and    -   n is an integer from 0 to 4; and preferably, n is selected from        0, 1 and 2; and    -   R2 is H or one or more substituents independently selected from        halogen, (1-4C)alkyl optionally substituted with one or more        fluoro atoms or (1-4C)alkoxy optionally substituted with one or        more fluoro atoms; and wherein the definition of the other        groups/symbols is as defined previously.

In another embodiment, the compound of the invention has the structure(Ia)

In an embodiment of the invention, ring structure Q is a 6-memberedring. In particular, the compound of the invention has the structure(Ib)

In a further embodiment of the invention, R4 is selected from—(CH₂)₂—OH, —CH₂—COOH, —(CH₂)₂—COOH, —(CH₂)₃—COOH, —CH₂—CHCH₃—COOH,—CH₂—C(CH₃)₂—COOH, —CHCH₃—CH₂—COOH, —CH₂—CF₂—COOH, —CO—CH₂—COOH,

1,3-cyclobutylene-COOH, —(CH₂)₂—PO₃H₂, —(CH₂)₃—PO₃H₂, —(CH₂)₂—OPO₃H₂,—(CH₂)₃—OPO₃H₂, —CH₂-tetrazol-5-yl, —(CH₂)₂-tetrazol-5-yl and—(CH₂)₃-tetrazol-5-yl. Preferred R4 groups are selected from—(CH₂)₂—COOH, —(CH₂)₃—COOH, —CH₂—CHCH₃—COOH, —CH₂—C(CH₃)₂—COOH,—CHCH₃—CH₂—COOH, —CH₂—CF₂—COOH and. Highly preferred are —(CH₂)₂—COOH,—CHCH₃—CH₂—COOH, —CH₂—CHCH₃—COOH and 1,3-cyclobutylene-COOH. Inparticular preferred is —CH₂—CHCH₃—COOH.

In another preferred embodiment, the compounds have formula (I) whereinY is O.

Further, in a preferred embodiment of the invention, X is N.

In preferred embodiments of the invention, R1 is indanyl optionallysubstituted with halogen, (1-4C)alkyl, or—more preferred—R1 isoptionally substituted phenyl, wherein the optional substituents areselected from any of the previously defined substituents, but inparticular the optional substituents are one or more substituentsindependently selected from halogen, cyano, (1-4C)alkyl, (1-4C)alkoxy,trifluoromethyl and trifluoromethoxy. In highly preferred embodiments,R1 is 4Cl-phenyl or 4CF₃-phenyl.

In an embodiment of the invention, R2 is H or one or more substituentsindependently selected from methyl, methoxy, chloro or fluoro. In apreferred embodiment, R2 is H or R2 represents one methyl, one methoxy,one chloro, one chloro, or one or two fluoro atoms.

In embodiments of the invention, wherein X is CR3, R3 is preferably H ormethyl and in particular, R3 is H.

Further, in an embodiment of the invention, Z is the linking group—W—(CH₂)_(n)-T-, the meaning of which is selected from a bond, —O—,—CO—, —S—, —SO₂—, —NH—, —CH₂—, —(CH₂)₂—, —CCH₃—O—, —CH═CH—, —C≡C—,—CH₂—O—, —O—CH₂—, —CH₂—S—, —S—CH₂—, —CH₂—SO₂—, —SO₂—CH₂—, —CH₂—NH—,—NH—CH₂—, and trans-cyclopropylene. In preferred embodiments, Z is —O—,—CH₂—O— or trans-cyclopropylene. In particular, Z is —CH₂—O—.

The term halogen refers to fluoro, chloro, bromo, or iodo. Preferredhalogens are fluoro and chloro, and in particular chloro.

The term (1-4C)alkyl means a branched or unbranched alkyl group having1-4 carbon atoms, for example methyl, ethyl, propyl, isopropyl andbutyl. A preferred alkyl group is methyl.

The term (1-4C)alkoxy means an alkoxy group having 1-4 carbon atoms,wherein the alkyl moiety is as defined above. A preferred alkoxy groupis methoxy.

The terms (1-4C)alkylene and (C_(n)-alkylene) mean a branched orunbranched alkylene group having 1-4 or n carbon atoms, respectively,for example methylene, —CHCH₃—, —C(CH₃)₂—, —CHCH₃CH₂—, and the like. Inthe definition of R4 which is (1-4C)alkylene-R5, one or more carbonatoms in the alkylene group may (amongst others) independently besubstituted with (CH₂)₂ to form a cyclopropyl moiety, meaning to form aR4 group such as

The term (2-4C)alkynyl means a branched or unbranched alkynyl grouphaving 2-4 carbon atoms, wherein the triple bond may be present atdifferent positions in the group, for example ethynyl, propargyl,1-butynyl, 2-butynyl, etc.

The term (3-6C)cycloalkyl means a cyclic alkyl group having 3-6 carbonatoms, thus cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.Preferred are cyclopentyl and cyclohexyl.

The term (4-6C)cycloalkenyl means a cyclic alkenyl group having 4-6carbon atoms and comprising one or two double bonds, for examplecyclohexenyl.

The term (3-6C)cycloalkylene means a cyclic alkyl group having twoattachment points. Preferred is 1,3-cyclobutylene, having the structure

The term (8-10C)bicyclic group means a fused ring system of two groupsselected from aromatic and non-aromatic ring structures having together8-10 carbon atoms, for example the indane group.

With reference to substituents, the term “independently” means that thesubstituents may be the same or different from each other in the samemolecule.

The compounds of the invention may suitably be prepared by methodsavailable in the art, and as illustrated in the experimental section ofthis description.

The compounds of the present invention may contain one or moreasymmetric centers and can thus occur as racemates and racemic mixtures,single enantiomers, diastereomeric mixtures and individualdiastereomers. Additional asymmetric centers may be present dependingupon the nature of the various substituents on the molecule. Each suchasymmetric center will independently produce two optical isomers and itis intended that all of the possible optical isomers and diastereomersin mixtures and as pure or partially purified compounds are includedwithin the ambit of this invention. The present invention is meant tocomprehend all such isomeric forms of these compounds. The independentsyntheses of these diastereomers or their chromatographic separationsmay be achieved as known in the art by appropriate modification of themethodology disclosed herein. Their absolute stereochemistry may bedetermined by the x-ray crystallography of crystalline products orcrystalline intermediates which are derivatized, if necessary, with areagent containing an asymmetric center of known absolute configuration.If desired, racemic mixtures of the compounds may be separated so thatthe individual enantiomers are isolated. The separation can be carriedout by methods well known in the art, such as the coupling of a racemicmixture of compounds to an enantiomerically pure compound to form adiastereomeric mixture, followed by separation of the individualdiastereomers by standard methods, such as fractional crystallization orchromatography.

Compounds may exist as polymorphs and as such are intended to beincluded in the present invention. In addition, compounds may formsolvates with water (i.e., hydrates) or common organic solvents, andsuch solvates are also intended to be encompassed within the scope ofthis invention.

Isotopically-labeled compound of formula (I) or pharmaceuticallyacceptable salts thereof, including compounds of formula (I)isotopically-labeled to be detectable by PET or SPECT, also fall withinthe scope of the invention. The same applies to compounds of formula (I)labeled with [¹³C]—, [¹⁴C]—, [³H]—, [¹⁸F]—, [¹²⁵I]— or otherisotopically enriched atoms, suitable for receptor binding or metabolismstudies.

The term “pharmaceutically acceptable salt” refers to those salts thatare, within the scope of sound medical judgment, suitable for use incontact with the tissues of humans and lower animals without unduetoxicity, irritation, allergic response, and the like, and arecommensurate with a reasonable benefit/risk ratio. Pharmaceuticallyacceptable salts are well-known in the art. They can be prepared in situwhen isolating and purifying the compounds of the invention, orseparately by reacting them with pharmaceutically acceptable non-toxicbases or acids, including inorganic or organic bases and inorganic ororganic acids.

The compounds of the invention may be administered enterally orparenterally. The exact dose and regimen of these compounds andcompositions thereof will be dependent on the biological activity of thecompound per se, the age, weight and sex of the patient, the needs ofthe individual subject to whom the medicament is administered, thedegree of affliction or need and the judgment of the medicalpractitioner. In general, parenteral administration requires lowerdosages than other methods of administration which are more dependentupon adsorption. However, the dosages for humans are preferably 0.001-10mg per kg body weight. In general, enteral and parenteral dosages willbe in the range of 0.1 to 1,000 mg per day of total active ingredients.

Mixed with pharmaceutically suitable auxiliaries, e.g. as described inthe standard reference “Remington, The Science and Practice of Pharmacy”(21^(st) edition, Lippincott Williams & Wilkins, 2005, see especiallyPart 5: Pharmaceutical Manufacturing) the compounds may be compressedinto solid dosage units, such as pills or tablets, or be processed intocapsules or suppositories. By means of pharmaceutically suitable liquidsthe compounds can also be applied in the form of a solution, suspensionor emulsion.

For making dosage units, e.g. tablets, the use of conventional additivessuch as fillers, colorants, polymeric binders and the like, iscontemplated. In general, any pharmaceutically suitable additive whichdoes not interfere with the function of the active compounds can beused.

Suitable carriers with which the compounds of the invention can beadministered include for instance lactose, starch, cellulose derivativesand the like, or mixtures thereof, used in suitable amounts.Compositions for intravenous administration may for example be solutionsof the compounds of the invention in sterile isotonic aqueous buffer.Where necessary, the intravenous compositions may include for instancesolubilizing agents, stabilizing agents and/or a local anesthetic toease the pain at the site of the injection.

Pharmaceutical compositions of the invention may be formulated for anyroute of administration and comprise at least one compound of thepresent invention and pharmaceutically acceptable salts thereof, withany pharmaceutically suitable ingredient, excipient, carrier, adjuvantor vehicle.

By “pharmaceutically suitable” it is meant that the carrier, diluent orexcipient must be compatible with the other ingredients of theformulation and not deleterious to the recipient thereof.

In an embodiment of the invention, a pharmaceutical pack or kit isprovided comprising one or more containers filled with one or morepharmaceutical compositions of the invention. Associated with suchcontainer(s) can be various written materials such as instructions foruse, or a notice in the form prescribed by a governmental agencyregulating the manufacture, use or sale of pharmaceuticals products,which notice reflects approval by the agency of manufacture, use, orsale for human or veterinary administration.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention pertains. Although methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, suitable methods andmaterials are described in this document.

LEGEND TO THE FIGURES

FIG. 1 Percentage of alternation of young and old C57BL/6J male mice inthe T-maze with either vehicle (control groups) or compound of theinvention (dose in mg/kg; p.o.)

The following examples are intended to further illustrate the inventionin more detail.

Any novel intermediate as disclosed herein is a further embodiment ofthe present invention.

EXAMPLES §1. Analytical Methods

Nuclear magnetic resonance spectra (¹H NMR and ¹³C NMR, APT) weredetermined in the indicated solvent using a Bruker ARX 400 (¹H: 400 MHz,¹³C: 100 MHz) at 300K, unless indicated otherwise. ¹⁹F NMR and ¹³C NMRexperiments were carried out on a Varian Inova 500 spectrometeroperating at 11.74 T (499.9 MHz for ¹H, 125.7 MHz for ¹³C, 50.7 Mhz,470.4 MHz for ¹⁹F) using a 5 mm SW probe. The spectra were determined indeuterated chloroform or DCM obtained from Cambridge IsotopeLaboratories Ltd. Chemical shifts (6) are given in ppm downfield fromtetramethylsilane (¹H, ¹³C) or CCl₃F (¹⁹F). Coupling constants J aregiven in Hz. Peak shapes in the NMR spectra are indicated with thesymbols ‘q’ (quartet), ‘dq’ (double quartet), ‘t’ (triplet), ‘dt’(double triplet), ‘d’ (doublet), ‘dd’ (double doublet), ‘s’ (singlet),‘bs’ (bs) and ‘m’ (multiplet). NH and OH signals were identified aftermixing the sample with a drop of D₂O.

Flash chromatography refers to purification using the indicated eluentand silica gel (either Acros: 0.030-0.075 mm or Merck silica gel 60:0.040-0.063 mm).

Column chromatography was performed using silica gel 60 (0.063-0.200 mm,Merck).

Reactions were monitored by using thin-layer chromatography (TLC) onsilica coated plastic sheets (Merck precoated silica gel 60 F254) withthe indicated eluent. Spots were visualized by UV light (254 nm) or 12.

Melting points were recorded on a Büchi B-545 melting point apparatus.

Liquid Chromatography-Mass Spectrometry (LC-MS):

Method A.

The LC-MS system consists of a Waters 1525 μ-pump. The pump is connectedto a Waters 2777 auto sampler.

The LC method is:

total flow step time (ul/min) A (%) B (%) 0 0.2  1600 90  10 1 2.5  1600 0 100 2 2.8  1600  0 100 3 2.9  1600 90  10 4 3.10 1600 90  10 5 3.11 500 90  10 A = 100% Water with 0.2% HCOOH B = 100% ACN with 0.2% HCOOH

The auto sampler has a 10 ul injection loop; the injection volume is101. The auto sampler is connected to a Waters Sunfire C18 30*4.6 mmcolumn with 2.5 um particles. The column is thermo stated at Roomtemperature +/−23° C.

The column is connected to a Waters 2996 PDA. The wavelength is scannedfrom 240 to 320 nm. The resolution is 1.2 nm and the sampling ate is 20Hz. After the PDA the flow is split 1:1 and connected to a Waters 2424ELSD.

The ELSD has the following parameters:

Gas pressure: 40 psi

Data rate 20 points/sec

Gain 500

Time constant 0.2 sec

Nebulizer mode cooling

Drift tube 50° C.

The samples are also measured with a Waters ZQ mass detector.

The mass spectrometer has the following parameters:

Scan range: 117-900 Amu

Polarity: positive

Data format: centroid

Time per scan: 0.500 sec

Interscan time: 0.05 sec

Capillary 2.5 kV Cone 25 V Extractor 2 V RF lens 0.5 V Source Temp. 125°C. Desolvation Temp 400° C. Cone gas 100 L/Hr Desolvation Gas 800 L/HrLM 1 Resolution 15 HM 1 Resolution 15 Ion energy 0.5 Multiplier 500 V

The complete system is controlled by Masslynx 4.1.

Method B.

The LC-MS system consists of 2 Perkin Elmer series 200 micro pumps. Thepumps are connected to each other by a 50 ul tee mixer. The mixer isconnected to the Gilson 215 auto sampler.

The LC method is:

total flow step time (ul/min) A (%) B (%) 0 0 1800 95   5 1 1.8 1800  0100 2 2.6 1800  0 100 3 2.8 1800 95   5 4 3.0 1800 95   5 A = 100% Waterwith 0.1% HCOOH B = 100% Acetonitril with 0.1% HCOOH

The auto sampler has a 2 ul injection loop. The auto sampler isconnected to a Waters Sunfire C18 4.6×30 mm column with 2.5 □mparticles. The column is thermo stated in a Perkin Elmer series 200column oven at 23° C. The column is connected to a Perkin Elmer 785UV/VIS meter with a 2.7 ul flow cell. The wavelength is set to 254 nm.The UV meter is connected to a Sciex API 150EX mass spectrometer. Themass spectrometer has the following parameters:

Scan range: 100-900 Amu

Polarity: positive

Scan mode: profile

Resolution Q1: UNIT

Step size: 0.10 amu

Time per scan: 0.500 sec

NEB: 10

CUR: 10

IS: 5200

TEM: 325

DF: 30

FP: 225

EP: 10

The light scattering detector is connected to the Sciex API 150. Thelight scattering detector is a Polymer Labs PL-ELS 2100 operating at 70°C. and 1.7 bar N₂ pressure.

The complete system is controlled by a Dell precision GX370 computeroperating under Windows 2000.

The reported retention times in Table 1 (Rt) are for the peak in theTotal Ion Current (TIC) chromatogram which showed the mass for [M+H]⁺within 0.5 amu accuracy of the calculated exact MW and had an associatedpeak in the Evaporative Light Scattering (ELS) chromatogram with arelative area % (purity) of >85%.

§2. Abbreviations

ACE-CI 1-Chloroethyl chloroformate 9-BBN 9-borabicyclo[3.3.1]nonanedimer CHCl₃ Chloroform CH₂Cl₂ Dichloromethane CH₃CN Acetonitrile CuBr2Copper(II) bromide DBU 1,8-Diazabicyclo[5.4.0]undec-7-ene DIADDiisopropyl azodicarboxylate DIPEA N,N-Diisopropylethylamine DMFN,N-dimethylformamide DMSO Dimethyl sulfoxide Et₃N Triethylamine Et₂ODiethyl ether EtOH Ethanol EtOAc Ethyl acetate HCl Hydrogen chlorideK₂CO₃ Potassium carbonate KHCO₃ Potassium bicarbonate KI Potassiumiodide KOH Potassium hydroxide KOtBu Potassium tert-butoxide MeOHMethanol NaBH₄ Sodium borohydride NaHCO₃ Sodium bicarbonate NaI Sodiumiodide NaOH Sodium hydroxide NaOtBu Sodium tert-butoxide Na₂SO₄ Sodiumsulfate NBS N-Bromosuccinimide iPr₂O Diisopropyl ether RT RoomTemperature SiO₂ Silica gel TFA Trifluoroacetic acid THF TetrahydrofuranTMSCl Chlorotrimethylsilane TMSOTf Trimethylsilyltrifluoromethanesulfonate

§3. General Aspects of Syntheses

Suitable syntheses of claimed compounds are described below.

For the synthesis of compounds 1, two routes are described inrespectively Schemes 2 and 3. Both routes start with compound 6, thesynthesis of which is depicted in Scheme 1. Alpha alkylation of thepyrrolidine-enamine of 4 with alpha-bromo-acetophenones (3)-therebyintroducing the Rb—group in the molecule—gives compound 5. Subsequentring-closure of 5 under acidic conditions yielded compound 6 in fairyields.

Route A (see Scheme 2) starts with the alkylation of the piperidinemoiety in 6 by either a standard alkylation, reductive alkylation orMichael addition reaction to give the protected carboxylic acidcompounds 7. The benzyl ether moiety could be introduced in two ways.Firstly, the bromine in 7 could be converted directly to the benzylether derivative 9 by a palladium catalyzed reaction. Additionally,bromide 7 can be converted to the phenol derivative 8 derivative via apalladium mediated reaction. Compound 8 can be converted to the desiredbenzyl ether derivatives 9 under phase transfer conditions with benzylbromides or via a Mitsunobu reaction with benzyl alcohols. Finally,compounds 9 could be deprotected to give the end-products 1.

Alternatively, Route B (see Scheme 3) could be followed for thesynthesis of compounds 1. The piperidine in compound 6 was protectedwith a BOC group. Hereafter, first the benzyl ether moiety wasintroduced either via a direct palladium mediated reaction of thebromine in 10 to 12 or via transforming the bromine to the phenolderivative 11, which could be converted to 12 under alkylation orMitsunobu conditions. Finally, compound 12 could be converted to 9 byacidic removal of the BOC group and subsequent introduction of theprotected carboxylic acid tails.

For the synthesis of oxazolo-derivatives 2, three routes were developed.The synthesis of key-intermediate 20 is depicted in Scheme 4. Acylationof commercially available 14 with a properly substituted benzoylchloride (15) gave 16, which was subsequently ring-closed to 17 by usingtriphenylphosphine and hexachloroethane. Methylation of the pyridine in17 to the quaternary salt 18 and subsequent reduction of 18 with sodiumborohydride yielded compound 19. Compound 19 was demethylated with1-chloroethyl chloroformate to furnish key-intermediate 20.

The first route (Route C) to compounds 2 is outlined in Scheme 5 andstarts from compound 20. In a similar fashion as described for thesynthesis of compounds 7 in the furanyl series, the t-butyl protectedcarboxylic acid tails could be introduced in 20 to give 21. Startingfrom 21, the benzyl ether derivatives 23 could be prepared by either adirect palladium mediated coupling (21 to 23) with benzyl alcohols or byfirst transforming the bromide in 21 to phenol 22 and subsequentbenzylation of 22 (to 23) under phase transfer or Mitsunobu conditions.Finally, acidic deprotection of the carboxylic acid in 23 yieldedcompounds 2.

Alternatively, route D could be followed as depicted in Scheme 6.Compounds 25 could be prepared starting from 14 and a properlysubstituted 4-benzyloxy-benzoic acid derivative (24) under the influenceof triphenylphosphine and trichloroacetonitril. Compound 25 could beconverted to the benzyloxy-derivatives 23 in a similar fashion asdescribed above in Schemes 4 and 5 for the synthesis of compounds 21.Thus, methylation of 25 and subsequent reduction with NaBH₄ gave 26,which was demethylated with ACE-C1 to give 27. Finally, the tails wereintroduced in 27 to give compound 23. From here, the t-butyl group in 23could be removed under acidic conditions to give compound 2. On theother hand, the benzyl in 23 can be removed by hydrogenation to givephenol derivatives 22.

And finally, the third route (Route E) to compounds 2 is depicted inScheme 7. Compound 20 was protected with a t-butyloxycarbonyl group togive 28, which could be converted to the corresponding phenol (29) understandard palladium conditions. Alkylation of 29 under phase transfer orMitsunobu conditions gave 30. On the other hand, compound 30 could alsobe obtained directly from the bromide 28 under palladium chemistryconditions. Acidic removal of the BOC group in 30 resulted in theformation of compound 27, which could be alkylated to 23 as described inScheme 5.

Thiazolo derivatives 508 and 520 were synthesized as described in Scheme8 and 9. Adjustments of R-groups in the reagents leads to theintroduction of Ra, Rb and Rc.

The synthetic route towards a number of alternative tails and linkers isdepicted in Scheme 10.

For those skilled in the art, it is clear that the choice for a certainroute can be based on the availability of the reagents. In addition, theroutes B, D and E are very suitable for the introduction of diversity inthe Rc-tail part of compounds 1 and 2. Routes A and C have theintroduction of the Ra-Bn moiety in the last part of the synthesis whichmakes it more suitable for exploring diversity in that part of themolecule.

§4. Syntheses of Intermediates

General Procedure for the Synthesis of Compounds 5.

To a solution of 4-oxo-piperidine-1-carboxylic acid t-butyl ester intoluene (2 ml/mmol) was added a catalytic amount ofpara-toluenesulphonic acid mono hydrate (0.1 eq) and pyrrolidine (4 eg).The mixture was heated to reflux under Dean Stark conditions for 18hours. The mixture was concentrated under reduced pressure and theresidue was redissolved in toluene. To this solution was added slowly(in 25 minutes) a solution of a properly substituted2-bromo-1-(4-bromo-phenyl)-ethanone (1.05 eq) in toluene/DCM (2 ml/mmol,1/2, v/v). The mixture was stirred overnight at room temperature and theresulting white slurry was poured out into water. The water layer wasextracted with DCM (3 times) and the combined organic layers were dried(MgSO₄) and subsequently concentrated under reduced pressure. Theresulting oil was purified by silica gel chromatography giving compound5 in a yield of 50-90%.

General Procedure for the Synthesis of Compounds 6.

Compound 5 was suspended in concentrated hydrochloric acid (10 eq, 12N).The mixture was heated (in steps of 10° C. per 30 minutes) to 80° C. Themixture starts to foam heavily, so allow enough volume in the startingreaction vessel. After 45 minutes, the mixture was cooled to 0° C. andneutralized with 50 wt % solution of NaOH (exothermic). After stirringovernight at room temperature, the resulting solid material wascollected by filtration and washed with 0.1M NaOH. The light brownmaterial was purified by Soxhlet extraction in EtOAc giving 6 as beigesolid which was used in the next step without further purification.

General Procedure for the Introduction of the Protected Carboxylic AcidTails (7).

a) Introduction of the Propionic Acid t-Butyl Ester.

Compound 6 was suspended in methanol (4 ml/mmol) and DIPEA was added(1.05 eg). To the mixture was added t-butyl acrylate (1.2 eq) and themixture was refluxed for 16 hrs. Conversion was checked by TLC analysis.The solvents were evaporated and the residue was redissolved in EtOAcand extracted with a 5% solution of NaHCO₃. The organic layer was dried(MgSO₄), concentrated in vacuo and the residue was purified by silicagel column chromatography to give pure 7a.

b) Introduction of the 2-Methyl-Propionic Acid t-Butyl Ester.

Compound 6 was suspended in DMF (6 ml/mmol). To this suspension wasadded 1,8-diazabicyclo[5.4.0]undec-7-ene (3 eg) and t-butyl methacrylate(2 eq). The mixture was heated at 125° C. for 16-100 hrs. The solutionwas cooled and 5% NaHCO₃ was added (15 ml/mmol) and extracted withEtOAc. The organic layer was washed with water (4×), dried on MgSO₄,concentrated in vacuo and the residue was purified by silica gel columnchromatography to give pure 7b.

c) Introduction of the 3-Butyric Acid t-Butyl Ester.

Compound 6 was suspended in 1,2-dichloroethane (6 ml/mmol). To thissuspension was added t-butylacetoacetate (1 eq) and sodium triacetoxyborohydride (1.4 eq). The mixture was stirred at room temperature for 16hrs. If the reaction was not complete, another portion oft-butylacetoacetate (1 eq) and sodium triacetoxy borohydride (1.4 eq)was added. To the solution was added 5% NaHCO₃ (15 ml/mmol) and themixture was extracted with DCM. The combined organic layers were driedon Na₂SO₄, concentrated in vacuo and the residue was purified by silicagel column chromatography to furnish pure 7c.

d)) Introduction of the 4-Butyric Acid t-Butyl Ester.

Compound 6 was suspended in acetonitril (3 ml/mmol). To this suspensionwas added potassium carbonate (2 eq), t-butyl 4-bromo-butanoate (1.1 eq)and potassium iodide (1.1 eq). The mixture was stirred at roomtemperature for 16 hrs after which time TLC analysis revealed completereaction. The mixture was concentrated in vacuo and the residue wasdissolved in EtOAc, washed with 5% NaHCO₃ (15 ml/mmol). The organiclayer was dried on Na₂SO₄, concentrated in vacuo and the residue waspurified by silica gel column chromatography to yield 7d.

General Procedure for the Introduction of the Benzyl Ether Moiety in 7to Compound 9.

A solution of compound 7, the properly substituted benzyl alcohol (1.1eq), palladium(II) acetate (0.02 eq),2-dit-butylphosphino-3,4,5,6-tertamethyl-2′,4′,6′-triisopropyl-1,1′biphenyl(0.02 eq), cesium carbonate (1.5 eq) in degassed toluene (4 ml/mmol) washeated at 75° C. for 16 hrs. Conversion was checked by TLC analysis. Thesolution was cooled to room temperature, diluted with DCM, filtered andconcentrated in vacuo. The residue was purified by silica gel columnchromatography to give compound 9 in yields varying from 30-80%.

General Procedure for the Conversion of the Bromine Derivatives 7 to thePhenol Derivatives 8.

Compound 7 was dissolved in toluene (8 mml/mmol) and to the solution wasadded potassium hydroxide (2 eq, 11.7N) and the solution was degassed.To the solution was added2-dit-butylphosphino-2′,4′,6′-triisopropylbiphenyl (0.06 eq) andtris-(dibenzylideneaceton)-dipalladium(0) (0.03 eq). The mixture wasstirred at 60° C. for 1.25 hrs. The mixture was allowed to reach roomtemperature, diluted with EtOAc and washed with 5% NaHCO₃ solution (10ml/mmol). The organic layers were dried on MgSO₄, filtered andconcentrated in vacuo. The residue was purified by silica gel columnchromatography to give compound 8 in yields varying from 25-85%.

General Procedure for the Conversion of the Phenol 8 to Benzyl Ethers 9.

Method A) Compound 8 was dissolved in DCM/water, 2/1, v/v (4 ml/mmol)and to this solution was added sodium hydroxide (2N, 3 eq). To thismixture were added tetrabutylammonium bromide (0.1 eq) and the properlysubstituted benzyl bromide (1.1 eq). The mixture was stirred for 16 hrsat room temperature after which time TLC analysis showed completereaction. The mixture was diluted with DCM (15 ml/mmol), the layers wereseparated and the water layer was extracted with DCM. The organic layerswere dried on MgSO₄, filtered and concentrated in vacuo. The residue waspurified by silica gel column chromatography to give compound pure 9 inyields varying from 80-90%.

Method B) Compound 8 was dissolved in N,N′-dimethylacetamide (4 ml/mmol)and to this solution was added triphenylphosphine (1.25 eq) anddiisopropyl azodicarboxylate (1.25 eq) and the properly substitutedbenzyl alcohol (1.2 eq). The mixture was stirred at room temperature for16 hrs after which time TLC analysis showed complete reaction. Themixture was diluted with diethyl ether and washed with water (3×). Thecombined organic layers were dried on MgSO₄, filtered and concentratedin vacuo. The residue was purified by silica gel column chromatographyto give compound 9 in yields varying from 70-90%.

General Procedure for the Acidic Deprotection of Compounds 9 to 1.

Compound 9 was dissolved in a solution of HCl in 1,4-dioxan (4N, 45 eq)and the mixture was stirred at room temperature for 24 hrs. Heating at50° C. was applied when needed to push the reaction to completion. Thesolvents were evaporated and diisopropyl ether was added to precipitatethe product. The white solid material was filtered and dried in vacuo togive compound 1 in a yield varying from 80-100%.

General Procedure for the Synthesis of the BOC Protected Derivatives of6.

To a suspension of compound 6 in DCM (6 ml/mmol) were added DIPEA (1eq), dimethylamino pyridine (DMAP, 0.05 eq) and di-t-butyl dicarbonate(1.1 eq). The mixture was stirred at room temperature for 16 hrs afterwhich time TLC analysis revealed complete reaction. The reaction mixturewas washed with 5% ag. NaHCO₃ solution and the resulting water layerswere extracted with DCM. The combined organic layers were dried onMgSO₄, filtered and concentrated in vacuo. The residue was purified bysilica gel column chromatography to give compound 10 in yields varyingfrom 70-90%.

General Procedure for the Synthesis of Compounds 11.

Compound 10 was dissolved in 1,4-dioxan/water, 1/1, v/v (2 ml/mmol) andto the solution was added potassium hydroxide (4 eq, 11.7N) and thesolution was degassed. To the solution was added2-dit-butylphosphino-2′,4′,6′-triisopropylbiphenyl (0.04 eq) andtris-(dibenzylideneaceton)-dipalladium(0) (0.02 eq). The mixture wasstirred at 80° C. for 16 hrs. The mixture was cooled to roomtemperature, diluted with EtOAc, acidified to pH 6 with 0.1N HCl andextracted with EtOAc. The organic layers were dried on MgSO₄, filteredand concentrated in vacuo. The residue was purified by silica gel columnchromatography to give pure compound 11 in yields varying from 60-95%.

General Procedure for the Synthesis of the Benzyl Ether Derivatives 12.

Method A) Compound 11 was dissolved in DCM/water, 2/1, v/v (4 ml/mmol)and to this solution was added sodium hydroxide (2N, 3 eq). To thismixture were added tetrabutylammonium bromide (0.1 eq) and the properlysubstituted benzyl bromide (1.1 eq). The mixture was stirred for 16 hrsat room temperature after which time TLC analysis showed completereaction. The mixture was diluted with DCM (15 ml/mmol), the layers wereseparated and the water layer was extracted with DCM. The organic layerswere dried on MgSO₄, filtered and concentrated in vacuo. The residue waspurified by silica gel column chromatography to give compound 12 inyields varying from 80-90%.

Method B) Compound 11 was dissolved in N,N′-dimethylacetamide (4ml/mmol) and to this solution was added triphenylphosphine (1.25 eq),diisopropyl azodicarboxylate (DIAD, 1.25 eq) and a properly substitutedbenzyl alcohol (1.2 eq). The mixture was stirred for 16 hrs at roomtemperature after which time TLC analysis showed complete reaction. Themixture was diluted with diethyl ether and washed with water (3×). Thecombined organic layers were dried on MgSO₄, filtered and concentratedin vacuo. The residue was purified by silica gel column chromatographyto give compound 12 in yields varying from 70-90%. Method C) Compound 10was dissolved in toluene (8 mml/mmol) and to the solution was addedpotassium hydroxide (2 eq, 11.7N) and the solution was degassed. To thesolution was added properly substituted benzyl bromide (1.1 eq),2-di-t-butylphosphino-2′,4′,6′-triisopropylbiphenyl (0.06 eq) andtris-(dibenzylideneaceton)-dipalladium(0) (0.03 eq). The mixture wasstirred at 60° C. for 1.25 hrs. The mixture was cooled to roomtemperature, diluted with EtOAc and washed with 5% NaHCO₃ solution (10ml/mmol). The organic layers were dried on MgSO₄, filtered andconcentrated in vacuo. The residue was purified by silica gel columnchromatography to give compound 12 in yields varying from 30-80%.

General Procedure for the Deprotection of Compounds 12 to 13.

Compound 12 was dissolved in DCM (10 ml/mmol) and trifluoroacetic acid(10 eq) was added. The solution was refluxed for 16 hrs after which timeTLC analysis showed complete reaction. The mixture was neutralized with5% aq. NaHCO₃. The mixture was extracted with DCM (3×) and the combinedorganic layers were washed with brine, dried on Na₂SO₄ and concentratedin vacuo to give compound 13 which was used in the next step withoutfurther purification.

General Procedure for the Introduction of the Protected Carboxylic AcidTails (9) Starting from Compound 13.

a) Introduction of the Propionic Acid t-Butyl Ester.

Compound 13 was suspended in methanol (4 ml/mmol) and DIPEA was added(1.05 eg). To the mixture was added 1.2 eg of t-butyl acrylate and themixture was refluxed for 16 hrs. Conversion was checked by TLC analysis.The solvents were evaporated and the residue was redissolved in EtOAcand extracted with a 5% solution of NaHCO₃. The organic layer was dried(MgSO₄), concentrated in vacuo and the residue was purified by silicagel column chromatography to give pure 9a.

b) Introduction of the 2-Methyl-Propionic Acid t-Butyl Ester.

To a solution of compound 13 in DMF (6 ml/mmol) in a pyrex bottle wasadded 1,8-diazabicyclo[5.4.0]undec-7-ene (3 eg) and t-butyl-methacrylate(2 eq). The mixture was heated at 125° C. for 100 hrs. The solution wascooled and 5% NaHCO₃ was added (15 ml/mmol) and extracted with diethylether/EtOAc, 1/1, v/v. The organic layer was washed with water (4×),dried on MgSO₄, concentrated in vacuo and the residue was purified bysilica gel column chromatography to give pure 9b.

c) Introduction of the 3-Butyric Acid t-Butyl Ester.

Compound 13 was suspended in 1,2-dichloroethane (6 ml/mmol). To thissuspension was added t-butylacetoacetate (1 eq) and sodium triacetoxyborohydride (1.4 eq). The mixture was stirred at room temperature for 16hrs. If the reaction was not complete, another portion oft-butylacetoacetate (1 eq) and sodium triacetoxy borohydride (1.4 eq)was added. After complete reaction, the solution was diluted with 5%NaHCO₃ (15 ml/mmol) and the mixture was extracted with DCM. The combinedorganic layers were dried on Na₂SO₄, concentrated in vacuo and theresidue was purified by silica gel column chromatography to furnish purecompound 9c.

d)) Introduction of the 4-Butyric Acid t-Butyl Ester.

Compound 13 was suspended in acetonitril (3 ml/mmol). To this suspensionwere added potassium carbonate (2 eq), t-butyl 4-bromo-butanoate (1.1eq) and potassium iodide (1.1 eq). The mixture was heated at roomtemperature for 16 hrs after which time TLC analysis revealed completereaction. The mixture was concentrated in vacuo and the residue wasdissolved in EtOAc, washed with 5% NaHCO₃ (15 ml/mmol). The organiclayer was dried on Na₂SO₄, concentrated in vacuo and the residue waspurified by silica gel column chromatography to yield compound 9d.

General Procedure for the Synthesis of2-(4-bromo-phenyl)-oxazolo[4,5-c]pyridine 17.

To a cooled (0° C.) suspension of commercially available4-hydroxy-3-amino-pyridine in DCM (14, 6 ml/mmol) was added triethylamine (1.25 eq) and a solution of properly substituted benzoyl chloride15 (1 eq, 0.3M in DCM). The reaction mixture was allowed to reach roomtemperature and the mixture was stirred for 16 to 64 hrs after whichtime TLC analysis showed complete reaction. The mixture was filtered,washed with DCM and ether to furnish 16 as a solid material (50-80%yield) which was used in the next step without further purification.Hexachloroethane (2.5 eq) was dissolved in DCM and triphenyl phosphine(3 eq) and triethyl amine (8 eq) was added. The mixture was stirred forminutes at room temperature and compound 16 was added slowly in 5 equalportions. The mixture was stirred at room temperature for 64 hrs afterwhich time TLC analysis (DCM/MeOH, 97/3, v/v) revealed completereaction. The solution was concentrated and the residue was suspended inDCM. The mixture was filtered and the residue washed with DCM anddiethyl ether to give 17 in a yield of 30-80%.

General Procedure for the Synthesis of Compounds 19.

To a solution of compound 17 in DMF was added iodomethane (4 eg) and themixture was stirred for 16 hrs. The mixture was concentrated in vacuoand the residue was stirred in EtOAc to give 18 as a white solid.Compound 18 was dissolved in methanol (10 ml/mmol) and the solution wascooled to 0° C. Sodium borohydride (2 eg) was added and the mixture wasstirred at 0° C. for 2 hrs after which time it was allowed to reach roomtemperature and stirring was continued for 16 hrs. Water was added (1ml/mmol) and the mixture was stirred for 5 minutes. The mixture wasco-evaporated with acetonitril and the residue was purified by silicagel column chromatography to yield compound 19 in 50-90%.

General Procedure for the Synthesis of Compounds 20.

To a cooled (0° C.) solution of compound 19 in 1,2-dichloroethane (10ml/mmol) was added DIPEA (2 eq). At 0° C. 1-chloroethyl chloroformate (3eq) was added and the mixture was stirred for 10 minutes at 0° C. afterwhich time the temperature was raised to reflux temperature. After 2hrs, the mixture was concentrated in vacuo and the residue was dissolvedin methanol (10 ml/mmol). The solution was stirred for 48 hrs at roomtemperature. Removal of the solvent resulted in the isolation ofcompound 20 in a yield of 70-90%.

General Procedure for the Synthesis of Compounds 21.

a) Introduction of the Propionic Acid t-Butyl Ester.

Compound 20 was suspended in methanol (10 ml/mmol) and DIPEA was added(2.05 eg). To the mixture was added 1.2 eg of t-butyl acrylate and themixture was refluxed for 16 to 120 hrs. Conversion was checked by TLCanalysis and when needed additional reagents were added to push thereaction to completion. The solvents were evaporated and the residue wasredissolved in EtOAc and extracted with a 5% solution of NaHCO₃. Theorganic layer was dried (MgSO₄), concentrated in vacuo and the residuewas purified by silica gel column chromatography to give 21a in yieldsvarying from 50-90%

b) Introduction of the 2-Methyl-Propionic Acid t-Butyl Ester.

To a solution of compound 20 in DMF (6 ml/mmol) was added1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, 3 eg) and t-butylmethacrylate(5 eq). The mixture was heated at 125° C. for 100 hrs. The solution wascooled and 5% NaHCO₃ was added (15 ml/mmol) and extracted with diethylether/EtOAc, 1/1, v/v. The organic layer was washed with water (4×),dried on MgSO₄, concentrated in vacuo and the residue was purified bysilica gel column chromatography to give pure 21b.

c) Introduction of the 3-Butyric Acid t-Butyl Ester.

Compound 20 was suspended in 1,2-dichloroethane (8 ml/mmol). To thissuspension were added t-butylacetoacetate (1.4 eq), acetic acid (leg)and sodium triacetoxy borohydride (1.8 eq). The mixture was stirred atroom temperature for 16 hrs. If the reaction was not complete, anotherportion of t-butylacetoacetate (1 eq) and sodium triacetoxy borohydride(1.4 eq) was added. After complete reaction, the solution was dilutedwith 5% NaHCO₃ (15 ml/mmol) and the mixture was extracted with DCM. Thecombined organic layers were dried on Na₂SO₄, concentrated in vacuo andthe residue was purified by silica gel column chromatography to furnishpure compound 21c.

d)) Introduction of the 4-Butyric Acid t-Butyl Ester.

Compound 20 was suspended in DMF (5 ml/mmol). To this suspension wasadded potassium carbonate (3 eq) and t-butyl 4-bromobutanoate (3 eq).The mixture was heated at 80° C. for 16 hrs after which time TLCanalysis revealed complete reaction. The mixture was concentrated invacuo and the residue was purified by silica gel column chromatographyto yield 21d.

General Procedure for the Synthesis of Compounds 22.

Compound 21 was dissolved in acetonitril (25 mml/mmol) and to thesolution was added powdered potassium hydroxide (2 eq) and the solutionwas degassed. To the solution was added2-dit-butylphosphino-3,4,5,6-tetramethyl-2′,4′,6′-triisopropyl-1,1-biphenyl(0.06 eq) and tris-(dibenzylideneaceton)-dipalladium(0) (0.03 eq). Themixture was stirred at 60° C. for 4 hrs. The mixture was cooled to roomtemperature and concentrated in vacuo. The residue was dissolved in DCMand washed with 0.1M HCl and water. The water layers were extracted withDCM and the combined organic layers was dried on MgSO₄. Compound 22 wasobtained after silica gel column chromatography in yields varying from30-70%.

General Procedure for the Introduction of the Benzyl Ether Moiety in 21to Compound 23.

A solution of compound 21, the properly substituted benzyl alcohol (2eq), palladium(II) acetate (0.02 eq),2-dit-butylphosphino-3,4,5,6-tetramethyl-2′,4′,6′-triisopropyl-1,1′biphenyl(0.02 eq), cesium carbonate (1.5 eq) in degassed toluene (3 ml/mmol) washeated at 75° C. for 16 hrs. Conversion was checked by TLC analysis. Thesolution was cooled to room temperature, diluted with DCM, filtered andconcentrated in vacuo. The residue was purified by silica gel columnchromatography to give compound pure 23 in yields varying from 30-80%.

General Procedure for the Conversion of the Phenol 22 to Benzyl Ethers23.

Method A) Compound 22 was dissolved in DCM/water, 2/1, v/v (4 ml/mmol)and to this solution was added sodium hydroxide (2N, 3 eq). To thismixture were added tetrabutylammonium bromide (0.1 eq) and a properlysubstituted benzyl bromide (1.1 eq). The mixture was stirred for 16 hrsat room temperature after which time TLC analysis showed completereaction. The mixture was diluted with DCM (15 ml/mmol), the layers wereseparated and the water layer was extracted with DCM. The organic layerswere dried on MgSO₄, filtered and concentrated in vacuo. The residue waspurified by silica gel column chromatography to give compound pure 23 inyields varying from 80-90%.

Method B) Compound 22 was dissolved in dry DCM (15 ml/mmol) and to thissolution were added triphenylphosphine (1.8 eq) and the properlysubstituted benzyl alcohol (1.8 eq). To this mixture was addeddiisopropyl azodicarboxylate (1.8 eq) and the mixture was stirred for 16hrs at room temperature after which time TLC analysis showed completereaction. The mixture was concentrated in vacuo. The residue waspurified by silica gel column chromatography to give compound pure 23 inyields varying from 70-90%.

Method C) PS-TBD (3.7 eq.) resin was incubated with a solution of 22(1.1 eg) in 1 mL of acetonitril for 1.5 h at 50° C. Thereafter, theproperly substituted benzyl bromide (1.10 eq.) in acetonitril was added.Subsequently, the reaction mixture was shaken and heated at 75° C. for16 hrs. Next, the solvent was removed by filtration and the resin waswashed with 3×2.5 mL ACN. The combined organics were concentrated invacuo, followed by flash column chromatography on silica to givecompound 23 in yields varying from 60-95%.

General Procedure for the Deprotection of 23 to Compounds 2.

Compound 23 was dissolved in a solution of HCl in 1,4-dioxan (4N, 100eq) and the mixture was stirred for 16 hrs at room temperature. Heatingat 50° C. was applied when needed to push the reaction to completion.The solvents were evaporated and diisopropyl ether was added toprecipitate the product. The white solid material was filtered and driedin vacuo to give compound 2 in a yield varying from 70-100%.

General Procedure for the Synthesis of Compounds 25.

To a cooled (0° C.) suspension of commercially available4-hydroxy-3-amino-pyridine (14) in acetonitril (15 ml/mmol) was added aproperly substituted 4-benzyloxy-benzoic acid (24, 1 eq),triphenylphosphine (3 eq) and trichloroacetonitril (3 eq). The reactionmixture was allowed to reach room temperature and the mixture wasstirred for 16 to 64 hrs at 80° C. The mixture was concentrated in vacuoand the residues was dissolved in DCM and washed with 2N NaOH (3×). Thecombined water layers were extracted with DCM and the organic layersdried (Na₂SO₄) to give crude 25 as oil which was used in the next stepwithout further purification.

General Procedure for the Synthesis of Compounds 26.

To a solution of compound 25 in DMF (5 ml/mmol) was added iodomethane (4eg) and the mixture was stirred for 16 hrs. The mixture was concentratedin vacuo and the residue was stirred in EtOAc to give the quaternarysalt of 25 as a white solid. The crude material was dissolved inmethanol (10 ml/mmol) and the solution was cooled to 0° C. Sodiumborohydride (2.5 eg) was added and the mixture was stirred at 0° C. for2 hrs after which time it was allowed to reach room temperature andstirring was continued for 16-64 hrs. Water was added (1 ml/mmol) andthe mixture was stirred for 5 minutes. The mixture was concentrated invacuo, the residues suspended in 2 N NaOH (5 ml/mmol) and extracted withDCM (3×). The combined organic layers were dried (Na₂SO₄) andconcentrated to give crude 26 as a yellow solid which was used in thenext step without further purification.

General Procedure to Compounds 27.

To a cooled (0° C.) solution of compound 26 in 1,2-dichloroethane (10ml/mmol) was added DIPEA (2 eq) and 1-chloroethyl chloroformate (3 eq)was added. The mixture was stirred for 10 minutes at 0° C. after whichtime the temperature was raised to reflux temperature. After 4 hrs, themixture was allowed to reach room temperature and stirring was continuedfor 16 hrs. The mixture was concentrated in vacuo and the residue wasdissolved in methanol (10 ml/mmol). The solution was stirred for 16-48hrs at room temperature. Removal of the solvent resulted in theisolation of crude 27 in an overall yield of 20-40% based on 25.

General Procedure for the Introduction of the Protected Carboxylic AcidTails (to 23) Starting from Compound 27.

a) Introduction of the Propionic Acid t-Butyl Ester.

Compound 27 was suspended in methanol (4 ml/mmol) and DIPEA was added(1.05 eg). To the mixture was added 1.2 eg of t-butyl acrylate and themixture was refluxed for 16 hrs. Conversion was checked by TLC analysis.The solvents were evaporated and the residue was redissolved in EtOAcand extracted with a 5% solution of NaHCO₃. The organic layer was dried(MgSO₄), concentrated in vacuo and the residue was purified by silicagel column chromatography to give pure 23a.

b) Introduction of the 2-Methyl-Propionic Acid t-Butyl Ester.

To a solution of compound 27 in DMF (6 ml/mmol) was added1,8-diazabicyclo[5.4.0]undec-7-ene (3 eg) and t-butylmethacrylate (4eq). The mixture was heated at 125° C. for 100 hrs. The solution wascooled and 5% NaHCO₃ was added (15 ml/mmol) and extracted with diethylether/EtOAc, 1/1, v/v. The organic layer was washed with water (4×),dried on MgSO₄, concentrated in vacuo and the residue was purified bysilica gel column chromatography to give pure 23b.

c) Introduction of the 3-Butyric Acid t-Butyl Ester.

Compound 27 was suspended in 1,2-dichloroethane (6 ml/mmol). To thissuspension was added t-butylacetoacetate (1 eq) and sodium triacetoxyborohydride (1.4 eq). The mixture was stirred at room temperature for 16hrs. If the reaction was not complete, another portion oft-butylacetoacetate (1 eq) and sodium triacetoxy borohydride (1.4 eq)was added. After complete reaction, the solution was diluted with 5%NaHCO₃ (15 ml/mmol) and the mixture was extracted with DCM. The combinedorganic layers were dried on Na₂SO₄, concentrated in vacuo and theresidue was purified by silica gel column chromatography to furnish purecompound 23c.

d)) Introduction of the 4-Butyric Acid t-Butyl Ester.

Compound 27 was suspended in acetonitril (3 ml/mmol). To this suspensionwas added potassium carbonate (2 eq), t-butyl 4-bromobutanoate (1.1 eq)and potassium iodide (1.1 eq). The mixture was heated at roomtemperature for 16 hrs after which time TLC analysis revealed completereaction. The mixture was concentrated in vacuo and the residue wasdissolved in EtOAc, washed with 5% NaHCO₃ (15 ml/mmol). The organiclayer was dried on Na₂SO₄, concentrated in vacuo and the residue waspurified by silica gel column chromatography to yield 23d.

e)) Introduction of the 3-Cyclobutanecarboxylic Acid.

Compound 27 was suspended in 1,2-dichloroethane (20 ml/mmol). To thissuspension was added 3-oxocyclobutanecarboxylic acid (1.3 eq) and sodiumtriacetoxy borohydride (1.6 eq). The mixture was stirred at roomtemperature for 16 hrs. If the reaction was not complete, anotherportion of 3-oxocyclobutanecarboxylic acid (1.3 eq) and sodiumtriacetoxy borohydride (1.6 eq) was added. After complete reaction, thesolution was diluted with 5% NaHCO₃ (15 ml/mmol) and the mixture wasextracted with DCM. The combined organic layers were dried on Na₂SO₄,concentrated in vacuo and the residue was purified by silica gel columnchromatography to furnish pure compound 2e.

General Procedure for the Hydrogenation of 23 to Compound 22.

To a solution of compound 23 in ethanol (10 ml/mmol) was added palladiumhydroxide on carbon (20%, 0.22 eg). Hydrogenation was started underatmospheric pressure of hydrogen. Stirring was continued for 16 hrs atroom temperature. The mixture was filtered over Hyflo and the residuewashed with ethanol. The filtrate was concentrated in vacuo to givecompound 22.

General Procedure for the Synthesis of Compounds 28.

To a suspension of compound 20 in DCM (6 ml/mmol) were added DIPEA (1eq), dimethylamino pyridine (DMAP, 0.05 eq) and di-t-butyl dicarbonate(1.1 eq). The mixture was stirred at room temperature for 16 hrs afterwhich time TLC analysis revealed complete reaction. The mixture wasconcentrated in vacuo. The residue was purified by silica gel columnchromatography to give compound pure 28 in yields varying from 70-90%.

General Procedure for the Synthesis of Compounds 29.

Compound 28 was dissolved in 1,4-dioxan/water, 1/1, v/v (10 ml/mmol) andto the solution was added potassium hydroxide (4 eq, 11.7N) and thesolution was degassed. To the solution was added2-di-t-butylphosphino-2′,4′,6′-triisopropylbiphenyl (0.04 eq) andtris-(dibenzylideneaceton)-dipalladium(0) (0.02 eq). The mixture wasstirred at 80° C. for 16 hrs. The mixture was cooled to roomtemperature, diluted with EtOAc, acidified to pH 6 with 0.1N HCl andextracted with EtOAc. The organic layers were dried on MgSO₄, filteredand concentrated in vacuo. The residue was purified by silica gel columnchromatography to give compound pure 29 in yields varying from 60-95%.

General Procedure for the Synthesis of the Benzyl Ether Derivatives 30.

Method A) Compound 29 was dissolved in DCM/water, 2/1, v/v (4 ml/mmol)and to this solution was added sodium hydroxide (2N, 3 eq). To thismixture was added tetrabutylammonium bromide (0.1 eq) and the properlysubstituted benzyl bromide (1.1 eq). The mixture was stirred for 16 hrsat room temperature after which time TLC analysis showed completereaction. The mixture was diluted with DCM (15 ml/mmol), the layers wereseparated and the water layer was extracted with DCM. The organic layerswere dried on MgSO₄, filtered and concentrated in vacuo. The residue waspurified by silica gel column chromatography to give compound pure 30 inyields varying from 80-90%.

Method B) Compound 29 was dissolved in N,N′-dimethylacetamide (4ml/mmol) and to this solution was added triphenylphosphine (1.25 eq),diisopropyl azodicarboxylate (1.25 eq) and a properly substituted benzylalcohol (1.2 eq). The mixture was stirred for 16 hrs at room temperatureafter which time TLC analysis showed complete reaction. The mixture wasdiluted with diethyl ether and washed with water (3×). The combinedorganic layers were dried on MgSO₄, filtered and concentrated in vacuo.The residue was purified by silica gel column chromatography to givecompound pure 30 in yields varying from 70-90%.

Method C) Compound 28 was dissolved in toluene (8 mml/mmol) and to thesolution was added potassium hydroxide (2 eq, 11.7N) and the solutionwas degassed. To the solution was added properly substituted benzylbromide (1.1 eq), 2-di-t-butylphosphino-2′,4′,6′-triisopropylbiphenyl(0.06 eq) and tris-(dibenzylideneaceton)-dipalladium(0) (0.03 eq). Themixture was stirred at 60° C. for 1.25 hrs. The mixture was cooled toroom temperature, diluted with EtOAc and washed with 5% NaHCO₃ solution(10 ml/mmol). The organic layers were dried on MgSO₄, filtered andconcentrated in vacuo. The residue was purified by silica gel columnchromatography to give compound pure 30 in yields varying from 30-80%.

General Procedure for the Deprotection of Compounds 30 to 27.

Compound 30 was dissolved in DCM (10 ml/mmol) and trifluoroacetic acid(6 eq) was added. The solution was refluxed for 16 hrs after which timeTLC analysis showed complete reaction. The mixture was neutralized with5% aq. NaHCO₃. The mixture was extracted with DCM (3×) and the combinedorganic layers were washed with brine, dried on Na₂SO₄ and concentratedin vacuo to give compound 27 which was used in the next step withoutfurther purification.

§5. Syntheses of Specific Compounds

(See Table 1)

All furanyl derivatives from Table 1 could be prepared by followingeither route A or B appropriate reagents. The following compounds aretypical examples.

All oxazolo derivatives from Table 1 could be prepared by followingeither route C, D or E by choosing the appropriate reagents. Thefollowing compounds are typical examples.

3-[2-(4-Bromo-phenyl)-2-oxo-ethyl]-4-oxo-piperidine-1-carboxylic acidt-butyl ester (5, Rb=H)

To a solution of 4-oxo-piperidine-1-carboxylic acid t-butyl ester (4,104.1 g, 522 mmol) in toluene (800 ml) was added a catalytic amount ofpara-toluenesulphonic acid mono hydrate (0.5 g, 2.6 mmol) andpyrrolidine (172.8 ml, 2090 mmol). The mixture was heated to refluxunder Dean Stark conditions for 18 hours. The mixture was concentratedunder reduced pressure and the residue was redissolved in toluene (600ml). To this solution was added slowly (in minutes) a solution of2-bromo-1-(4-bromo-phenyl)-ethanone (3, Rb=H, 145.2 g, 522 mmol) intoluene/DCM (900 ml, 1/2, v/v). The mixture was stirred overnight atroom temperature and the resulting white slurry was poured out in water(1.5 L). The water layer was extracted with DCM (3×300 ml) and thecombined organic layers were dried (MgSO₄) and subsequently concentratedunder reduced pressure. The resulting oil was purified by silica gelchromatography (diethyl ether/petroleum ether, 2/3, v/v to 100% diethylether) giving compound 5 (Rb=H, 166.6 g, 87%) as a yellow solid. TLCanalysis, Rf 0.3 in diethyl ether/petroleum ether, 1/1, v/v.

2-[4-Bromo-phenyl]-4,5,6,7-tetrahydro-furo[3,2-c]pyridine (6, Rb=H)

Compound 5 (Rb=H, 166 g, 456 mmol) was suspended in concentratedhydrochloric acid (500 ml, 12N, 6 mol). The mixture was heated with 10°C. per 30 minutes to 80° C. The mixture starts to foam heavily, so allowenough volume in the starting reaction vessel. After 45 minutes, themixture was cooled to 0° C. and neutralized with 50 wt % solution ofNaOH (exothermic). After stirring overnight at room temperature, theresulting solid material was collected by filtration and washed with 250ml 0.1M NaOH. The light brown material was purified by Soxhletextraction in EtOAc giving 6 (Rb=H, 51 g, 38%) as a beige solid whichwas used in the next step without further purification. LC-MS (MethodA): Rt 1.19, [M+H] 278.

3-[2-(4-Bromo-phenyl)-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl]-propionicacid t-butyl ester (7a, Rb=H)

Compound 6 (Rb=H, 1.46 g, 5 mmol) was suspended in methanol (30 ml) andDIPEA was added (0.91 ml, 1.05 eg). To the mixture was added t-butylacrylate (0.88 ml, 1.2 eq) and the mixture was refluxed for 16 hrs.Conversion was checked by TLC analysis (diethyl ether/petroleum ether,1/1, v/v). The solvents were evaporated and the residue was redissolvedin EtOAc and extracted with a 5% solution of NaHCO₃. The organic layerwas dried (MgSO₄), concentrated in vacuo and the residue was purified bysilica gel column chromatography (diethyl ether/petroleum ether, 2/3 to1/1, v/v) to give pure 7a (Rb=H, 1.75 g, 86%) as a white solid. LC-MS(Method A): Rt 1.38, [M+H] 407.

3-[2-(4-Hydroxy-phenyl)-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl]-propionicacid t-butyl ester (8a, Rb=H)

Compound 7a (Rb=H, 3.85 g, 9.5 mmol) was dissolved in toluene (80 ml)and to the solution was added potassium hydroxide (2 eq, 11.7N) and thesolution was degassed. To the solution was added2-di-t-butylphosphino-2′,4′,6′-triisopropylbiphenyl (0.24 g, 0.57 mmol,0.06 eq) and tris-(dibenzylideneaceton)-dipalladium(0) (0.26 g, 0.28mmol, 0.03 eq). The mixture was stirred at 60° C. for 1.25 hrs. Themixture was cooled to room temperature, diluted with EtOAc and washedwith 5% NaHCO₃ solution (10 ml/mmol). The organic layers were dried onMgSO₄, filtered and concentrated in vacuo. The residue was purified bysilica gel column chromatography (diethyl ether/petroleum ether, 1/1,v/v, Rf 0.1) to give pure compound 8a (Rb=H, 1.86 g, 57%) as a yellowsolid. LC-MS (Method A): Rt 1.14, [M+H] 344.

3-{2-[4-(2-Fluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-propionicacid t-butyl ester (9a, Ra=2F, Rb=H)

Compound 8a (Rb=H, 1.24 g, 3.61 mmol) was dissolved inN,N-dimethylacetamide (10 ml) and to this solution was addedtriphenylphosphine (1.33 g, 5.06 mmol, 1.4 eq), diisopropylazodicarboxylate (1 ml, 5.05 mmol, 1.4 eq) and 2-fluorobenzyl alcohol(0.46 ml, 4.33 mmol, 1.2 eq). The mixture was stirred for 16 hrs at roomtemperature after which time TLC analysis (diethyl ether, Rf 0.3) showedcomplete reaction. The mixture was diluted with diethyl ether and washedwith water (3×). The combined organic layers were dried on MgSO₄,filtered and concentrated in vacuo. The residue was purified by silicagel column chromatography (diethyl ether/petroleum ether, 1/1, v/v to2/1, v/v) to give compound pure 9a (Ra=2F, Rb=H, 1.38 g, 84%) as an oil.LC-MS (Method A): Rt 1.46, [M+H] 452.

3-{2-[4-(2-Fluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-propionicacid (33)

Compound 9a (Ra=2F, Rb=H, 1.38 g, 3.1 mmol) was dissolved in a solutionof HCl in 1,4-dioxan (4N, 30 ml) and the mixture was stirred for 2 hrsat 35° C. The solvents were evaporated and diisopropyl ether (30 ml) wasadded to precipitate the product as the hydrochloric acid salt. Thewhite solid material was filtered and dried in vacuo to give compound 33(0.75 g, 54%) as a white solid. ¹H NMR (400 MHz, DMSO-d₆): δ ppm 2.93(t, J=7.6 Hz, 2H), 3.07 (bs, 2H), 3.28-3.55 (bs, 2H), 3.44 (t, J=7.6 Hz,2H), 3.60-3.90 (bs, 2H), 4.06-4.56 (bs, 2H), 5.17 (s, 2H), 6.76 (s, 1H),7.10 (d, J=8.8 Hz, 2H), 7.21-7.31 (m, 2H), 7.39-7.48 (m, 1H), 7.57 (t,J=7.5 Hz, 1H), 7.63 (d, J=8.8 Hz, 2H), 10.7-11.5 (bs, 1H), 12.3-13.2(bs, 1H); LC-MS (Method A): Rt 1.39, [M+H] 396.

2-(4-Bromo-phenyl)-6,7-dihydro-4H-furo[3,2-c]pyridine-5-carboxylic acidt-butyl ester 10 (Rb=H)

To a suspension of compound 6 (Rb=H, 5 g, 17 mmol) in DCM (100 ml) wereadded DIPEA (2.92 ml, 1 eq), DMAP (0.1 g, 0.05 eq) and di-t-butyldicarbonate (4.1 g, 18.8 mmol, 1.1 eq). The mixture was stirred at roomtemperature for 16 hrs after which time TLC analysis (DCM, Rf, 0.40)revealed complete reaction. The reaction mixture was washed with 5% ag.NaHCO₃ solution and the resulting water layers were extracted with DCM.The combined organic layers were dried on MgSO₄, filtered andconcentrated in vacuo. The residue was purified by silica gel columnchromatography (eluent: 100% DCM) to give compound 10 (Rb=H, 5.99 g,92%) as an oil.

2-(4-Hydroxy-phenyl)-6,7-dihydro-4H-furo[3,2-c]pyridine-5-carboxylicacid t-butyl ester 11a (Rb=H)

Compound 10 (Rb=H, 11.77 g, 31 mmol) was dissolved in 1,4-dioxan/water,1/1, v/v (200 ml) and to the solution was added potassium hydroxide(6.98 g, 124.5 mmol, 4 eq) and the solution was degassed. To thesolution was added 2-di-t-butylphosphino-2′,4′,6′-triisopropylbiphenyl(0.53 g, 1.24 mmol, 0.04 eq) andtris-(dibenzylideneaceton)-dipalladium(0) (0.57 g, 0.62 mmol, 0.02 eq).The mixture was stirred at 80° C. for 16 hrs. The mixture was cooled toroom temperature, diluted with EtOAc, acidified to pH 6 with 0.1N HCland extracted with EtOAc. The organic layers were dried on MgSO₄,filtered and concentrated in vacuo. The residue was purified by silicagel column chromatography (eluent: DCM/MeOH, 1/0 to 99.5/0.5) to givecompound 11 (Rb=H, 9 g, 90%) as a white solid.

2-[4-(4-Chloro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-carboxylicacid t-butyl ester (12, Ra=4Cl, Rb=H)

Compound 11a (Rb=H, 2.0 g, 6.34 mmol) was dissolved in DCM/water, 2/1,v/v (30 ml) and to this solution was added sodium hydroxide (2N, 10 ml).To this mixture was added tetrabutylammonium bromide (0.2 g, 0.63 mmol,0.1 eq) and 4-chlorobenzyl bromide (1.43 g, 6.98 mmol, 1.1 eg). Themixture was stirred for 16 hrs at room temperature after which time TLCanalysis (100% DCM, Rf 0.55) showed complete reaction. The mixture wasdiluted with DCM (15 ml/mmol), the layers were separated and the waterlayer was extracted with DCM. The organic layers were dried on MgSO₄,filtered and concentrated in vacuo. The residue was purified by silicagel column chromatography (DCM/petroleum ether, 3/1 to 1/0, v/v) to givecompound 12 (Ra=4Cl, Rb=H, 2.3 g, 82%) as a yellow oil. ¹H NMR (400 MHz,CDCl₃) δ ppm 1.4 (s, 9H); 2.75 (bs, 2H); 3.75 (bs, 2H); 4.35 (bs, 2H);5.05 (s, 2H); 6.4 (s, 1H), 6.94 (d, 1H); 7.30-755 (m, 7H).

2-[4-(4-Chloro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine(13, Ra=4Cl, Rb=H)

Compound 12 (Ra=4Cl, Rb=H, 2.3 g, 5.2 mmol) was dissolved in DCM (50 ml)and trifluoroacetic acid (4 ml, 10 eq) was added. The solution wasrefluxed for 16 hrs after which time TLC analysis (100% DCM, Rf 0.05)showed complete reaction. The mixture was neutralized with 5% aq.NaHCO₃. The mixture was extracted with DCM (3×) and the combined organiclayers were washed with brine, dried on Na₂SO₄ and concentrated in vacuoto give crude 13 (Ra=4Cl, Rb=H, 1.79 g) which was used in the next stepwithout further purification. LC-MS (Method A): Rt 1.49, [M+H] 340.

3-{2-[4-(4-Chloro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-2-methyl-propionicacid t-butyl ester (9b, Ra=4Cl, Rb=H)

To a solution of compound 13a (0.25 g, 0.74 mmol) in DMF (5 ml) in a 25ml pyrex bottle were added 1,8-diazabicyclo[5.4.0]undec-7-ene (0.33 ml,2.21 mmol) and t-butylmethacrylate (0.24 ml, 1.47 mmol). The mixture washeated at 140° C. for 16 hrs. The solution was cooled and 5% NaHCO₃ wasadded (10 ml) and extracted with diethyl ether/EtOAc, 1/1, v/v. Theorganic layer was washed with water (4×20 ml), dried on MgSO₄,concentrated in vacuo and the residue was purified by silica gel columnchromatography (diethyl ether/petroleum ether, 9/1 to 4/1, v/v, Rf 0.65)to give pure 9b (Ra=4Cl, Rb=H, 0.1 g, 28%) as a colorless oil. LC-MS(Method A): Rt 1.88, [M+H] 482.

3-{2-[4-(4-Chloro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-2-methyl-propionicacid (77)

Compound 9b (Ra=4Cl, Rb=H, 0.12 g, 0.25 mmol) was dissolved in asolution of HCl in 1,4-dioxan (4N, 2.8 ml) and the mixture was stirredfor 16 hrs at room temperature. The solvent was evaporated anddiisopropyl ether (30 ml) was added to precipitate the product as thehydrochloric acid salt. The white solid material was filtered and driedin vacuo to give compound 77 (0.09 g, 74%) as a white solid. ¹H NMR (400MHz, DMSO-d₆): δ ppm 1.29 (d, J=7.2 Hz, 3H), 3.05-3.17 (m, 3H), 3.23(dd, J=5.4, 13.3 Hz, 1H), 3.51-3.68 (m, 3H), 4.24 (br. s., 2H), 5.16 (s,2H), 6.73 (s, 1H), 7.08 (d, J=8.9 Hz, 2H), 7.42-7.53 (m, 4H), 7.61 (d,J=8.9 Hz, 2H), 10.4-13.1 (bs, 2H); ¹³C NMR (101 MHz, DMSO-d₆): δ ppm16.42 (q, 1C), 20.36 (t, 1C), 35.17 (d, 1C), 48.74 (t, 1C), 49.57 (t,1C), 56.96 (t, 1C), 68.60 (t, 1C), 102.92 (d, 1C), 113.06 (s, 1C),115.41 (d, 1C), 123.20 (s, 1C), 124.87 (d, 1C), 128.41 (d, 1C), 129.42(d, 1C), 132.46 (s, 1C), 136.01 (s, 1C), 145.10 (s, 1C), 152.99 (s, 1C),157.85 (s, 1C), 174.95 (s, 1C). LC-MS (Method A): Rt 1.56, [M+H] 426.

2-[4-(Benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-carboxylicacid t-butyl ester 12 (Ra=Rb=H)

Compound 11 (Rb=H, 0.84 g, 2.66 mmol) was dissolved in DCM/water, 2/1,v/v (30 ml) and to this solution was added sodium hydroxide (2N, 4.2ml). To this mixture was added tetrabutyl-ammonium bromide (0.09 g, 0.27mmol, 0.1 eq) and benzyl bromide (0.35 ml, 2.93 mmol, 1.1 eg). Themixture was stirred for 16 hrs at room temperature after which time TLCanalysis (DCM/MeOH, 98/2, v/v, Rf 0.8) showed complete reaction. Themixture was diluted with DCM (100 ml), the layers were separated and thewater layer was extracted with DCM. The organic layers were dried onMgSO₄, filtered and concentrated in vacuo. The residue was purified bysilica gel column chromatography (DCM/petroleum ether, 3/1 to 1/0, v/v)to give compound 12 (Ra=Rb=H, 1.03 g, 95%) as a white solid. ¹H NMR (400MHz, CDCl₃) δ ppm 1.4 (s, 9H); 2.75 (bs, 2H); 3.75 (bs, 2H); 4.35 (bs,2H); 5.05 (s, 2H); 6.35 (s, 1H); 6.98 (d, 2H); 7.30-7.55 (m, 7H).

2-[4-Benzyloxy-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine (13, Ra=Rb=H)

Compound 12 (Ra=Rb=H, 1.03 g, 2.54 mmol) was dissolved in DCM (20 ml)and trifluoroacetic acid (1.5 ml) was added. The solution was refluxedfor 16 hrs after which time TLC analysis (100% DCM, Rf 0.05) showedcomplete reaction. The mixture was neutralized with 5% aq. NaHCO₃ (40ml) and extracted with DCM (3×50 ml) and the combined organic layerswere washed with brine, dried on Na₂SO₄ and concentrated in vacuo togive compound 13 (Ra=Rb=H, 0.67 g, 86%) which was used in the next stepwithout further purification. LC-MS (Method A): Rt 1.50, [M+H] 306.

3-{2-[4-Benzyloxy-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-butyricacid t-butyl ester (9c, Ra=Rb=H)

Compound 13 (Ra=Rb=H, 0.16 g, 0.52 mmol) was suspended in1,2-dichloroethane (3.2 ml). To this suspension was addedt-butylacetoacetate (0.09 ml, 0.52 mmol) and sodium triacetoxyborohydride (0.16 g, 0.73 mmol). The mixture was stirred at roomtemperature for 16 hrs, after which time another portion oft-butylacetoacetate (1 eq) and sodium triacetoxy borohydride (1.4 eq)were added together with a drop of acetic acid. After stirring foranother 60 hrs, again a portion of t-butylacetoacetate (1 eq) and sodiumtriacetoxy borohydride (1.4 eq) were added and stirring was continuedfor 36 hrs. The solution was diluted with 5% NaHCO₃ (10 ml) and themixture was extracted with DCM (3×100 ml). The combined organic layerswere dried on Na₂SO₄, concentrated in vacuo and the residue was purifiedby silica gel column chromatography (diethyl ether/petroleum ether, 9/1to 4/1, v/v) to furnish pure compound 9c (Ra=Rb=H, 0.06 g, 25%) as awhite solid. LC-MS (Method A): Rt 1.68, [M+H] 448.

3-{2-[4-Benzyloxy-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-butyricacid (76)

Compound 9c (Ra=Rb=H, 0.08 g, 0.18 mmol) was dissolved in a solution ofHCl in 1,4-dioxan (4 ml, 2N) and the mixture was stirred for 16 hrs atroom temperature. The solvents were evaporated and the residue wasco-evaporated with cyclohexane. Diisopropyl ether (30 ml) was added toprecipitate the product as the hydrochloric acid salt, the white solidmaterial was filtered and dried in vacuo to give compound 76 (0.06 g,80%). ¹H NMR (400 MHz, DMSO-d₆), δ ppm: 1.38 (d, J=6.6 Hz, 3H),2.58-2.75 (m, 1H), 2.90-3.18 (m, 3H), 3.39-3.54 (m, 1H), 3.61-3.78 (m,1H), 3.80-3.93 (m, 1H), 4.13-4.32 (m, 2H), 5.14 (s, 2H), 6.76 (s, 1H),7.07 (d, J=8.8 Hz, 2H), 7.30-7.36 (m, 1H), 7.40 (s, 2H), 7.45 (s, 2H),7.62 (d, J=8.8 Hz, 2H), 10.15-10.80 (m, 1H), 12.54-13.10 (m, 1H). LC-MS(Method A): Rt 1.46, [M+H] 392.

4-[2-(4-Bromo-phenyl)-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl]-butyricacid t-butyl ester (7d)

Compound 6 (Rb=H, 4.55 g, 16.3 mmol) was suspended in acetonitril (55ml). To this suspension were added potassium carbonate (4.52 g, 32.7mmol), t-butyl 4-bromobutanoate (4.38 g, 19.6 mmol, 1.2 eq) andpotassium iodide (3.2 g, 19.6 mmol, 1.2 eq). The mixture was heated toreflux for 16 hrs after which time TLC analysis (diethyl ether/petroleumether, 1/1, v/v, Rf 0.1) revealed complete reaction. The mixture wasconcentrated in vacuo and the residue was dissolved in EtOAc and washedwith 5% NaHCO₃ (2×60 ml). The organic layer was dried on Na₂SO₄,concentrated in vacuo and the residue was purified by silica gel columnchromatography (diethyl ether/petroleum ether, 1/1, v/v) to yield 7d(Rb=H, 4.94 g, 71%) as a yellow solid. LC-MS (Method A): Rt 1.37, [M+H]420.

4-[2-(4-Hydroxy-phenyl)-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl]-butyricacid t-butyl ester (8d)

Compound 7d (Rb=H, 4.91 g, 11.68 mmol) was dissolved in toluene (100 ml)and to the solution was added potassium hydroxide (2 ml, 11.7N) and thesolution was degassed. To the solution was added2-di-t-butylphosphino-2′,4′,6′-triisopropylbiphenyl (0.27 g, 0.64 mmol,0.06 eq) and tris-(dibenzylideneaceton)-dipalladium(0) (0.29 g, 0.32mmol, 0.03 eq). The mixture was stirred at 60° C. for 1.25 hrs. Themixture was cooled to room temperature, diluted with EtOAc and washedwith 5% NaHCO₃ solution (100 ml). The organic layers were dried onMgSO₄, filtered and concentrated in vacuo. The residue was purified bysilica gel column chromatography (diethyl ether/petroleum ether, 1/1 to1/0, v/v, Rf 0.1) to give pure compound 8d (Rb=H, 4.0 g) as a yellowsolid. LC-MS (Method A): Rt 1.21, [M+H] 358.

4-{2-[4-(2-Fluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-butyricacid t-butyl ester (9d)

Compound 8d (Rb=H, 0.43 g, 1.2 mmol) was dissolved in DCM/water, 2/1,v/v (5 ml) and to this solution was added sodium hydroxide (1.8 ml, 2N,3 eq). To this mixture was added tetrabutylammonium bromide (0.1 eq) and2F-benzyl bromide (1.32 mmol, 250 mg). The mixture was stirred for 16hrs at room temperature after which time TLC analysis (diethyl ether, Rf0.5) showed complete reaction. The mixture was diluted with DCM (15 ml),the layers were separated and the water layer was extracted with DCM.The organic layers were dried on MgSO₄, filtered and concentrated invacuo. The residue was purified by silica gel column chromatography(diethyl ether/petroleum ether, 1/1 to 1/0, v/v to give compound 9d(Ra=2F, Rb=H) in a yield of 80%. LC-MS (Method A): Rt 1.49, [M+H] 466.

4-{2-[4-(2-Fluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-butyricacid (35)

Compound 9d (Ra=2F, Rb=H, 0.3 g, 0.64 mmol) was dissolved in a solutionof HCl in 1,4-dioxan (4N, 2.8 ml) and the mixture was stirred for 16 hrsat room temperature. The solvents were evaporated and diisopropyl ether(30 ml) was added to precipitate the product as the hydrochloric acidsalt. The white solid material was filtered and dried in vacuo to givecompound 35 (0.32 g, 95%) as a white solid. ¹H NMR (400 MHz, DMSO-d₆) □PPM: 1.69-1.83 (m, 2H), 2.18 (t, J=7.2 Hz, 2H), 2.81-2.91 (m, 2H),3.02-3.13 (m, 2H), 3.23-3.36 (bs, 1H), 3.50-3.68 (bs, 1H), 3.89-4.05 (m,1H), 4.15-4.29 (m, 1H), 4.98 (s, 2H), 6.58 (s, 1H), 6.91 (d, J=8.7 Hz,2H), 7.02-7.12 (m, 2H), 7.21-7.29 (m, 1H), 7.38 (dt, J=7.7, 1.5 Hz, 1H),7.44 (d, J=8.7 Hz, 2H), 9.80 (br.s., 1H), 11.37-13.06 (bs, 1H); LC-MS(Method A): Rt 1.37, [M+H] 410.

4-{2-[4-(2-Fluoro-benzyloxy)-2-fluoro-phenyl]-6,7-dihydro-4H-furo[3,2-c]-pyri-dine-5-yl}-butyricacid (73)

Compound 73 was prepared in a similar fashion as described for 35starting from 2-bromo-1-(4-bromo-2-fluoro-phenyl)-ethanone. Compound 73:¹H NMR (400 MHz, DMSO-d₆), □ PPM: 1.92-2.04 (m, 2H), 2.38 (t, J=7.1 Hz,2H), 3.02-3.13 (m, 2H), 3.17-3.28 (m, 2H), 3.44-3.92 (bs, 2H), 3.98-4.54(bs, 2H), 5.21 (s, 2H), 6.70 (d, J=2.8 Hz, 1H), 7.00 (dd, J=8.9, 1.9 Hz,1H), 7.12 (dd, J=13.4, 1.9 Hz, 1H) 7.23-7.32 (m, 2H) 7.41-7.50 (m, 1H)7.56-7.63 (m, 1H) 7.69 (t, J=9.0 Hz, 1H), 10.06-10.93 (bs, 1H),12.07-12.85 (bs, 1H); LC-MS (Method A): Rt 1.35, [M+H] 428.

2-(4-Bromo-phenyl)-oxazolo[4,5-c]pyridine (17, Rb=H)

To a cooled (0° C.) suspension of commercially available4-hydroxy-3-amino-pyridine 14 (4 g, 36 mmol) in DCM (200 ml) were addedtriethyl amine (6.3 ml, 1.25 eq) and a solution of 4-bromo-benzoylchloride (15, Rb=H, 8 g, 36 mmol, 1 eq, 0.3M in DCM). The reactionmixture was allowed to reach room temperature and the mixture wasstirred for 16 hrs. The mixture was filtered, washed with DCM and etherto furnish crude 16 (Rb=H) as a solid material which was used in thenext step without further purification. Hexachloroethane (10.2 g, 43mmol, 2.5 eq) was dissolved in DCM (150 ml) and triphenyl phosphine(13.56 g, 51.69 mmol, 3 eq) and triethyl amine (19.2 ml, 137.8 mmol, 8eq) was added. The mixture was stirred for minutes at room temperatureand crude compound 16 (Rb=H) was added slowly in 5 equal portions. Themixture was stirred at room temperature for 64 hrs after which time TLCanalysis (DCM/MeOH, 97/3, v/v, Rf 0.3) revealed complete reaction. Thesolution was concentrated and the residue was suspended in DCM. Themixture was filtered and the residue washed with DCM and diethyl etherto give crude 17 (Rb=H) which was used in the next step without furtherpurification.

2-(4-Bromo-phenyl)-5-methyl-4,5,6,7-tetrahydro-oxazolo[4,5-c]pyridine(19, Rb=H)

To a solution of compound 17 (Rb=H, 11.4 mmol) in DMF (95 ml) was addediodomethane (2.84 ml, 45.58 mmol, 4 eg) and the mixture was stirred for16 hrs. The mixture was concentrated in vacuo and the residue wasstirred in EtOAc to give crude 18 (Rb=H, 3.3 g, 69%) as a white solid.Compound 18 (Rb=H, 2.3 g, 5.5 mmol) was dissolved in methanol (55 ml)and the solution was cooled to 0° C. Sodium borohydride (0.42 g, 11mmol, 2 eg) was added and the mixture was stirred at 0° C. for 2 hrsafter which time it was allowed to reach room temperature and stirringwas continued for 16 hrs. Water was added (4 ml) and the mixture wasstirred for 5 minutes. The mixture was co-evaporated with acetonitriland the residue was purified by silica gel column chromatography (DMA0.5) to yield compound 19 (Rb=H) in a yield of 61%.

2-(4-Bromo-phenyl)-4,5,6,7-tetrahydro-oxazolo[4,5-c]pyridine (20, Rb=H)

To a cooled (0° C.) solution of compound 19 (Rb=H, 0.95 g, 3.2 mmol) in1,2-dichloroethane (32 ml) was added DIPEA (1.1 ml, 6.4 mmol, 2 eq). At0° C., 1-chloroethylchloroformate (1.05 ml, 9.72 mmol, 3 eq) was addedand the mixture was stirred for 10 minutes at 0° C. after which time thetemperature was raised to reflux temperature. After 2 hrs, the mixturewas concentrated in vacuo and the residue was dissolved in methanol (35ml). The solution was stirred for 48 hrs at room temperature. Theprecipitate was filtered, the solid product was washed with diethylether to give compound 20 (Rb=H, 0.9 g, 88%). LC-MS (Method A): Rt 1.1,[M+H] 280.

3-[2-(4-Bromo-phenyl)-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl]-propionicacid t-butyl ester (21, Rb=H)

Compound 20 (Rb=H, 8 g, 22.8 mmol) was suspended in methanol (200 ml)and DIPEA was added (8.15 ml, 46.8 mmol, 2.05 eg). To the mixture wasadded t-butyl acrylate (3.97 ml, 27.4 mmol, 1.2 eq) and the mixture wasrefluxed for 120 rs. Conversion was checked by TLC analysis and after 16and 64 hrs additional t-butyl acrylate (3.97 ml, 27.4 mmol, 1.2 eq) wasadded to push the reaction to completion. The solvents were evaporatedand the residue was redissolved in EtOAc and extracted with a 5%solution of NaHCO₃. The organic layer was dried (MgSO₄), concentrated invacuo and the residue was purified by silica gel column chromatography(eluent: diethyl ether/petroleum ether, 1/1, v/v) to give 21a (Rb=H, 8.8g, 93%). LC-MS (Method A): Rt 1.38, [M+H] 408.

3-{2-[4-(Benzyloxy)-phenyl)]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-propionicacid t-butyl ester (23a, Ra=Rb=H)

Compound 21a (Rb=H, 0.9 g, 2.21 mmol) was dissolved in degassed toluene(7 ml) and to the solution was added cesium carbonate (1.08 g, 3.3mmol), benzyl alcohol (0.46 ml, 4.42 mmol, 2 eq),2-di-t-butylphosphino-3,4,5,6-tetramethyl-2′,4′,6′-triisopropyl-1,1-biphenyl(25.5 mg, 0.05 mmol, 0.02 eq) and palladium(II) acetate (9.92 mg, 0.04mmol, 0.02 eq). The mixture was stirred at 70° C. for 16 hrs. Themixture was cooled to room temperature, concentrated in vacuo and theresidue was purified by silica gel column chromatography (diethylether/petroleum ether, 3/1, v/v) to give pure 23a (Ra=Rb=H, 0.71 g, 74%)as a white solid. LC-MS (Method A): Rt 1.46, [M+H] 435.

3-{2-[4-(Benzyloxy)-phenyl)]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-propionicacid (47)

Compound 23a (Ra=Rb=H, 0.71 g, 1.63 mmol) was dissolved in a solution ofHCl in 1,4-dioxan (4N, 12 ml, 30 eq) and the mixture was stirred for 16hrs at 50° C. The solvents were evaporated and diethyl ether was addedto precipitate the product. The white solid material was filtered anddried in vacuo to give compound 47 (0.67 g, 93%) as a white solid. ¹HNMR (400 MHz, DMSO-d₆): □ ppm, 2.92 (t, J=7.1 Hz, 2H), 3.06-3.31 (bs,2H), 3.57 (t, J=7.1 Hz, 2H), 3.50-3.61 (bs, 1H), 3.79-4.04 (bs, 1H),4.21-4.42 (bs, 1H), 4.42-4.60 (bs, 1H), 5.20 (s, 2H), 7.16 (d, J=8.6 Hz,2H), 7.35 (t, J=7.5 Hz, 1H), 7.41 (t, J=7.5 Hz, 2H), 7.49 (d, J=7.5 Hz,2H), 7.93 (d, J=8.6 Hz, 2H), 10.31-10.84 (bs, 1H). LC-MS (Method A): Rt1.32, [M+H] 379.

4-[2-(4-Bromo-phenyl)-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl]-butyricacid t-butyl ester (21d, Rb=H)

Compound 20 (Rb=H, 2.5 g, 7.92 mmol) was suspended in DMF (40 ml). Tothis suspension was added potassium carbonate (3.8 g, 27.7 mmol, 3.5 eq)and t-butyl 4-bromobutanoate (5.3 g, 23.7 mmol, 3 eq). The mixture washeated at 80° C. for 16 hrs after which time TLC analysis revealedcomplete reaction. The mixture was concentrated in vacuo and the residuewas purified by silica gel column chromatography (eluent: diethylether/petroleum ether, 1/1, v/v to 100% diethyl ether) to yield 21d(Rb=H, 3.15 g, 94%) as a white solid.

4-{2-[4-(2,3-Difluoro-benzyloxy)-phenyl)]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid t-butyl ester (23d, Ra=2,3-diF, Rb=H)

Compound 21d (Rb=H, 0.6 g, 1.42 mmol) was dissolved in degassed toluene(5 ml) and to the solution was added cesium carbonate (0.7 g, 2.14mmol), 2,3-difluoro-benzyl alcohol (0.32 ml, 2.85 mmol, 2 eq),2-di-t-butylphosphino-3,4,5,6-tetramethyl-2′,4′,6′-triisopropyl-1,1-biphenyl(16.43 mg, 0.03 mmol, 0.02 eq) and palladium(II) acetate (6.39 mg, 0.03mmol, 0.02 eq). The mixture was stirred at 70° C. for 16 hrs. Themixture was cooled to room temperature, concentrated in vacuo and theresidue was purified by silica gel column chromatography (diethylether/petroleum ether, 2/1, v/v to 100% diethyl ether) to give pure 23d(Ra=2,3-diF, Rb=H, 0.48 g, 70%) as an oil.

4-{2-[4-(2,3-Difluoro-benzyloxy)-phenyl)]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid (57)

Compound 23d (Ra=2,3-diF, Rb=H, 0.46 g, 0.95 mmol) was dissolved in asolution of HCl in 1,4-dioxan (4N, 14 ml, 60 eq) and the mixture wasstirred for 16 hrs at room temperature. The solvents were evaporated anddiethyl ether was added to precipitate the product. The white solidmaterial was filtered and dried in vacuo to give compound 57 (0.45 g,99%) as a white solid. ¹H NMR (400 MHz, DMSO-d₆): □□ ppm 2.08 (m., 2H),2.41 (t, J=7.0 Hz, 2H), 3.00-3.29 (m, 2H), 3.31-3.40 (m, 2H), 3.48-3.70(bs, 1H), 3.70-3.96 (bs, 1H), 4.18-4.38 (m, 1H), 4.38-4.61 (m, 1H), 5.26(s, 2H), 7.16 (d, J=8.8 Hz, 2H), 7.19-7.25 (m, 1H), 7.28-7.39 (m, 2H),7.94 (d, J=8.8 Hz, 2H), 10.37-10.88 (bs, 1H); LC-MS (Method A): Rt 1.16,[M+H] 429.

4-{2-[4-Benzyloxy-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid (53)

Compound 53 was prepared in a similar fashion as described for thesynthesis of 57 starting from 23d (Ra=Rb=H). ¹H NMR (400 MHz, DMSO-d₆):□ ppm 2.01-2.17 (m, 2H), 2.42 (t, J=6.9 Hz 2H), 3.00-3.30 (m, 2H),3.32-3.41 (m, 2H), 3.50-3.69 (m, 1H), 3.78-3.96 (m, 1H), 4.18-4.37 (m,1H), 4.43-4.59 (m, 1H), 5.18 (s, 2H), 7.14 (d, J=8.8 Hz, 2H), 7.34 (t,J=7.9 Hz, 1H), 7.40 (t, J=7.9 Hz, 2H), 7.47 (d, J=7.9 Hz, 2H), 7.93 (d,J=8.8 Hz, 2H), 10.45-10.89 (bs, 1H); LC-MS (Method A): Rt 1.17, [M+H]393.

4-{2-[4-(4-Trifluoromethyl-benzyloxy)-2-fluoro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid (85)

Compound 85 was prepared following route C starting from2-fluoro-4-bromo-benzoyl chloride. ¹H NMR (400 MHz, DMSO-d₆), □ ppm:1.98-2.11 (m, 2H), 2.40 (t, J=7.1 Hz, 2H), 3.10-3.24 (m, 2H), 3.30-3.42(m, 2H), 3.51-3.66 (bs, 1H), 3.79-3.97 (bs, 1H), 4.25-4.39 (m, 1H),4.49-4.65 (m, 1H), 5.32 (s, 2H), 6.98-7.13 (m, 2H), 7.66-7.78 (m, 4H),7.93 (t, J=8.6 Hz, 1H), 9.91-10.46 (bs, 1H); LC-MS (Method A): Rt 1.77,[M+H] 479.

4-{2-[4-(2-Fluoro-benzyloxy)-2-methyl-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid (89)

Compound 89 was prepared following route C starting from2-methyl-4-bromo-benzoyl chloride. ¹H NMR (400 MHz, DMSO-d₆), □ ppm:2.00-2.12 (m, 2H), 2.41 (t, J=7.1 Hz, 2H), 2.64 (s, 3H), 3.05-3.26 (m,2H), 3.32-3.42 (m, 2H), 3.50-3.70 (bs, 1H), 3.79-3.95 (bs, 1H),4.22-4.39 (m, 1H), 4.48-4.65 (m, 1H), 5.21 (s, 2H), 6.97-7.04 (m, 2H),7.17-7.27 (m, 2H), 7.37-7.46 (m, 1H), 7.56 (dt, J=7.4, 1.4 Hz, 1H), 7.89(d, J=8.5 Hz, 1H), 9.97-10.46 (bs, 1H); LC-MS (Method A): Rt 1.61, [M+H]425.

4-{2-[4-(3,4-Dichloro-benzyloxy)-2-fluoro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid (227)

Compound 227 was prepared following route C starting from2-fluoro-4-bromo-benzoyl chloride. ¹H NMR (600 MHz, DMSO-d₆), □ ppm:1.74 (q, J=7.1 Hz, 2H), 2.26 (t, J=7.1 Hz, 2H), 2.55 (t, J=7.1 Hz, 2H),2.73-2.78 (m, 2H), 2.81 (t, J=5.3 Hz, 2H), 3.43 (br.s, 2H), 5.21 (s,2H), 7.00 (dd, J=8.8, 2.5 Hz, 1H), 7.11 (dd, J=13.0, 2.5 Hz, 1H), 7.47(dd, J=8.4, 2.0 Hz, 1H), 7.69 (d, J=8.3 Hz, 1H), 7.76 (d, J=1.9 Hz, 1H),7.89 (t, J=8.3 Hz, 1H), 11.30-12.80 (bs, 1H); LC-MS (Method A): Rt 1.42,[M+H] 479.

4-{2-[4-(2-Fluoro-benzyloxy)-3-chloro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid (283)

Compound 283 was prepared following route C starting from3-chloro-4-bromo-benzoyl chloride. ¹H NMR (400 MHz, DMSO-d₆): □ ppm1.69-1.801.74 (m, 2H), 2.27 (t, J=7.2 Hz, 2H), 2.55 (t, J=7.0 Hz, 2H),2.73-2.79 (m, 2H), 2.81 (t, J=4.6 Hz, 2H), 3.43 (s, 2H), 5.32 (s, 2H),7.25-7.33 (m, 2H), 7.42-7.50 (m, 2H), 7.58-7.65 (m, 1H), 7.88 (dd,J=8.7, 2.1 Hz, 1H), 7.93 (d, J=2.1 Hz, 1H), 11.0-13.0 (bs, 1H); LC-MS(Method B): Rt 1.99*, [M+H] 445.

4-{2-[4-(4-Chloro-benzyloxy)-3-fluoro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid (211)

Compound 211 was prepared following route C starting from3-fluoro-4-bromo-benzoyl chloride. ¹H NMR (400 MHz, DMSO-d₆) □ ppm:1.95-2.06 (m, 2H), 2.38 (t, J=7.2 Hz, 2H), 3.09-3.20 (m, 2H), 3.23-3.32(m., 2H), 3.44-3.53 (m, 1H), 3.76-3.86 (m, 1H), 4.20-4.32 (m, 1H),4.43-4.52 (m, 1H), 5.28 (s, 2H), 7.43 (t, J=8.6 Hz, 1H), 7.51 (m, 4H),7.76 (m, 2H), 10.65-11.02 (bs, 1H), 12.03-12.77 (bs, 1H); LC-MS (MethodB): Rt 2.03*, [M+H] 445.

2-(4-Benzyloxy-phenyl)-oxazolo[4,5-c]pyridine (25, Ra=Rb=H)

To a cooled (0° C.) suspension of commercially available4-hydroxy-3-amino-pyridine (14, 19.3 g, 175 mmol) in acetonitril (1500ml) was added 4-benzyloxy-benzoic acid (24, Ra=Rb=H, 40 g, 175 mmol),triphenylphosphine (142.5 g, 543 mmol, 3.1 eq) and trichloroactonitril(54.5 ml, 543 mmol, 3.1 eq). The reaction mixture was allowed to reachroom temperature and the mixture was stirred for 16 hrs at 80° C. Themixture was concentrated in vacuo and the residues was dissolved in DCMand washed with 2N NaOH (3×). The combined water layers were extractedwith DCM and the organic layers dried (Na₂SO₄) to give crude 25(Ra=Rb=H) as oil which was used in the next step without furtherpurification.

2-(4-Benzyloxy-phenyl)-5-methyl-4,5,6,7-tetrahydro-oxazolo[4,5-c]pyridine(26, Ra=Rb=H)

To a solution of crude 25 (Ra=Rb=H, 117 mmol) in DMF (540 ml) was addediodomethane (29.35 ml, 471 mmol, 4 eg) and the mixture was stirred for16 hrs. The mixture was concentrated in vacuo and the residue wasstirred in EtOAc to give the quaternary salt of 25 a white solid, whichdissolved in methanol (950 ml) and the solution was cooled to 0° C.Sodium borohydride (10.2 g, 268 mmol, 2.5 eg) was added and the mixturewas stirred at 0° C. for 2 hrs after which time it was allowed to reachroom temperature and stirring was continued for 64 hrs. Water was added(117 ml) and the mixture was stirred for 5 minutes. The mixture wasconcentrated in vacuo, the residues suspended in 2N NaOH (5 ml/mmol) andextracted with DCM (3×). The combined organic layers were dried (Na₂SO₄)and concentrated to give crude 26 (Ra=Rb=H) as a yellow solid which wasused in the next step without further purification.

2-(4-Benzyloxy-phenyl)-4,5,6,7-tetrahydro-oxazolo[4,5-c]pyridine (27,Ra=Rb=H)

To a cooled (0° C.) solution of compound 26 (Ra=Rb=H, 35.2 g, 109.8mmol) in 1,2-dichloroethane (880 ml) was added DIPEA (37.61 ml, 219.7mmol, 2 eq) and 1-chloroethyl chloroformate (35.56 ml, 329.6 mmol, 3 eq)was added. The mixture was stirred for 10 minutes at 0° C. after whichtime the temperature was raised to reflux temperature. After 4 hrs, themixture was allowed to reach room temperature and stirring was continuedfor 16 hrs. The mixture was concentrated in vacuo and the residue wasdissolved in methanol (880 ml). The solution was stirred for 16 hrs atroom temperature after which time TLC analysis revealed the reaction tobe complete. Removal of the solvent resulted in the isolation of crude27 (Ra=Rb=H) in an overall yield of 20% based on 25 (Ra=Rb=H).

3-[2-(4-Benzyloxy-phenyl)-4,5,6,7-tetrahydro-oxazolo[4,5-c]pyridine]-2-methyl-propionicacid t-butyl ester (28b)

To a solution of compound 27 (Ra=Rb=H, 13.45 g, 43.9 mmol) in DMF (270ml) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (3 eg) andt-butylmethacrylate (28.54 ml, 175.6 mmol, 4 eq). The mixture was heatedat 125° C. for 100 hrs. The solution was cooled and 5% NaHCO₃ was added(15 ml/mmol) and extracted with diethyl ether/EtOAc, 1/1, v/v. Theorganic layer was washed with water (4×), dried on MgSO₄, concentratedin vacuo and the residue was purified by silica gel columnchromatography (eluent: diethyl ether/petroleum ether, 1/2 to 3/1, v/v)to give 23b (Ra=Rb=H, 14.58 g, 74%) as an oil.

3-[2-(4-Benzyloxy-phenyl)-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl]-2-methyl-propionicacid (146)

Compound 23b (Ra=Rb=H, 0.45 g, 1 mmol) was dissolved in a solution ofHCl in 1,4-dioxan (4N, 14 ml, 60 eq) and the mixture was stirred for 16hrs at room temperature. The solvents were evaporated and diethyl etherwas added to precipitate the product. The white solid material wasfiltered and dried in vacuo to give compound 146 (0.43 g, 99%) as awhite solid. ¹H NMR (400 MHz, DMSO-d₆), □ ppm: 1.28 (d, J=7.3 Hz, 3H),3.07-3.20 (m, 3H), 3.26 (dd, J=13.2, 4.9 Hz, 1H), 3.60 (dd, J=13.2, 7.9Hz, 1H), 3.66 (bs, 2H), 4.34 (br. s., 2H), 5.18 (s, 2H), 7.11-7.17 (m,2H), 7.31-7.37 (m, 1H), 7.37-7.43 (m, 2H), 7.44-7.49 (m, 2H), 7.85-7.93(m, 2H), 10.17-12.85 (bs, 1H); LC-MS (Method A): Rt 1.48, [M+H] 393.

3-{2-[4-(4-Trifluoromethyl-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-2-methyl-propionicacid (156)

Compound 156 was prepared following Route C. ¹H NMR (400 MHz, DMSO-d₆):□ ppm: 1.29 (d, J=7.2 Hz, 3H), 3.09-3.21 (bs, 3H), 3.27 (dd, J=13.1, 5.3Hz, 1H), 3.57-3.72 (dd, J=13.1, 7.3 Hz, 1H), 3.65-3.72 (bs, 2H), 4.34(br. s., 2H), 5.33 (s, 2H), 7.21 (d, J=8.8 Hz, 2H), 7.68-7.74 (m, 2H),7.75-7.81 (m, 2H), 7.93 (d, J=8.8 Hz, 2H), 10.50-12.32 (bs, 1H); ¹³C NMR(101 MHz, DMSO-d₆), □ PPM: 16.35 (q, 1C), 19.25 (t, 1C), 35.14 (d, 1C),49.04 (br. t., 1C), 49.76 (br. t., 1C), 57.23 (t, 1C), 68.66 (t, 1C),115.60 (d, 2C), 119.65 (s, 1C), 124.21 (s, ¹JCF=272.5 Hz, 1C), 125.34(d, ³JCF=3.6 Hz, 2C), 127.63 (d, 2C), 128.05 (d, 2C), 128.51 (s,²JCF=31.7 Hz, 1C), 128.63 (s, 1C), 141.51 (s, 1C), 142.86 (s, 1C),160.11 (s, 1C), 160.76 (s, 1C), 174.95 (s, 1C); LC-MS (Method A): Rt1.82, [M+H] 461.

3-{2-[4-(4-Chloro-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-2-methyl-propionicacid (157)

Compound 157 was prepared following route C. ¹H NMR (400 MHz, DMSO-d₆),□ ppm: 1.19 (d, J=7.4 Hz, 3H), 3.00-3.12 (m, 3H), 3.18 (dd, J=13.2, 5.3Hz, 1H), 3.52 (dd, J=13.2, 7.1 Hz, 1H), 3.56-3.66 (bs, 2H), 4.24 (br.s., 2H), 5.11 (s, 2H), 7.08 (d, J=9.0 Hz, 2H), 7.35-7.43 (m, 4H), 7.81(d, J=9.0 Hz, 2H), 10.57-11.92 (bs, 1H); ¹³C NMR (101 MHz, DMSO-d₆), □PPM: 16.44 (q, 1C), 19.19 (t, 1C), 35.09 (d, 1C), 49.1 (br. t., 1C),49.6 (br. t., 1C), 57.17 (t, 1C), 68.72 (t, 1C), 115.59 (d, 2C), 119.50(s, 1C), 127.60 (d, 2C), 128.45 (d, 2C), 128.52 (s, 1C), 129.51 (d, 2C),132.58 (s, 1C), 135.69 (s, 1C), 142.79 (s, 1C), 160.22 (s, 1C), 160.80(s, 1C), 174.92 (s, 1C); LC-MS (Method A): Rt 1.72, [M+H] 427.

3-{2-[4-(2,3-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid (175)

Compound 175 was prepared following route C. ¹H NMR (400 MHz, DMSO-d₆),δ ppm: 1.27 (d, J=6.6 Hz, 3H), 2.5-2.6 (m, 1H), 2.8-3.1 (m, 3H), 3.1-3.5(bs, 2H), 3.6-3.7 (bs, 1H), 3.9-4.1 (bs, 2H), 5.28 (s, 2H), 7.0-7.2 (m,2H), 7.2-7.3 (m, 1H), 7.4-7.5 (m, 2H), 7.9-8.0 (m, 2H), 12.16 (br. s.,1H); LC-MS (Method A): Rt 1.3, [M+H] 429.

3-{2-[4-(4-Trifluoromethyl-benzyloxy)-2-fluoro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-2-methyl-propionicacid (271)

Compound 271 was prepared following route C. ¹H NMR (400 MHz, DMSO-d₆),□ ppm: 1.29 (d, J=7.2 Hz, 3H), 3.06-3.36 (m, 4H), 3.51-3.68 (m, 2H),3.70-3.90 (bs, 1H), 4.18-458 (bs, 2H), 5.33 (s, 2H), 7.03 (dd, J=8.7,2.2 Hz, 1H), 7.10 (dd, J=12.9, 2.2 Hz, 1H), 7.65-7.71 (m, 2H), 7.73-7.77(m, 2H), 7.92 (t, J=8.7 Hz, 1H), 11.01 (br. s., 1H); LC-MS (Method A):Rt 1.56, [M+H] 479.

2-(4-Bromo-phenyl)-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-carboxylicacid t-butyl ester (28, Rb=H)

To a suspension of compound 20 (Rb=H, 14.3 g, 48.2 mmol) in DCM (300 ml)were added DIPEA (1 eq) and di-t-butyl dicarbonate (11.59 g, 53 mmol,1.1 eq). The mixture was stirred at room temperature for 16 hrs afterwhich time TLC analysis revealed complete reaction. The mixture wasconcentrated in vacuo to give crude compound pure 28 (Rb=H) which wasused in the next step without further purification.

2-(4-Hydroxy-phenyl)-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-carboxylicacid t-butyl ester (29, Rb=H)

Compound 28 (Rb=H, 9 g, 20.4 mmol) was dissolved in 1,4-dioxan (90 ml)and to the solution was added potassium hydroxide (4.58 g, 81 mmol, in90 ml water) and the solution was degassed. To the solution was added2-di-t-butylphosphino-2′,4′,6′-triisopropylbiphenyl (346 mg, 0.82 mmol,0.04 eq) and tris-(dibenzylideneaceton)-dipalladium(0) (373.5 mg, 0.41mmol, 0.02 eq). The mixture was stirred at 80° C. for 16 hrs after whichtime LC-MS analysis showed that the conversion was complete. The mixturewas cooled to room temperature, diluted with EtOAc, acidified to pH 6with 0.1N HCl and extracted with EtOAc. The organic layers were dried onMgSO₄, filtered and concentrated in vacuo. The residue was purified bysilica gel column chromatography (DCM/MeOH, 97/3, v/v) to give compoundpure 29 (Rb=H, 6 g, 83%).

2-[4-(4-Trifluoromethyl-benzyloxy)-phenyl)-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-carboxylicacid t-butyl ester (30, Ra=4CF₃, Rb=H)

Compound 29 (Rb=H, 6 g, 17 mmol) was dissolved in DCM/water, 2/1, v/v(78 ml/mmol) and to this solution was added sodium hydroxide (27 ml, 2N,3 eq). To this mixture was added tetrabutylammonium bromide (549 mg, 0.1eq) and 4-trifluoromethyl-benzyl bromide (4.48 g, 18.75 mmol, 1.1 eq).The mixture was stirred for 16 hrs at room temperature after which timeLC-MS analysis showed complete reaction. The mixture was diluted withDCM (200 ml), the layers were separated and the water layer wasextracted with DCM. The organic layers were dried on MgSO₄, filtered andconcentrated in vacuo. The residue was purified by silica gel columnchromatography (eluent: EtOAc/petroleum ether, 1/3) to give compoundpure 30 (Rb=H, 9.0 g, 96%) as a colorless foam.

2-[4-(4-Trifluoromethyl-benzyloxy)-phenyl)-6,7-dihydro-H-oxazolo[4,5-c]pyridine(30, Ra=4CF₃, Rb=H)

Compound 30 (9.6 g, 18.5 mmol) was dissolved in DCM (150 ml) andtrifluoroacetic acid (8.5 ml, 111 mmol, 6 eq) was added. The solutionwas refluxed for 16 hrs after which time TLC analysis showed completereaction. The mixture was neutralized with 5% aq. NaHCO₃. The mixturewas extracted with DCM (3×) and the combined organic layers were washedwith brine, dried on Na₂SO₄ and concentrated in vacuo to give compound27 (Ra=4CF₃, Rb=H) which was used in the next step without furtherpurification.

3-{2-[4-(4-Trifluoromethoxybenzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-cyclobutanecarboxylic acid (306)

Compound 27 (Ra=4CF₃, Rb=H 0.71 g, 1.8 mmol) was suspended in1,2-dichloroethane (40 ml).

To this suspension was added 3-oxocyclobutanecarboxylic acid (0.27 g,2.34 mmol, 1.3 eq) and sodium triacetoxy borohydride (0.61 g, 2.88 mmol,1.6 eq). The mixture was stirred at room temperature for 16 hrs afterwhich time TLC analysis revealed complete reaction. The solution wasdiluted with 5% NaHCO₃ (15 ml/mmol) and the mixture was extracted withDCM. The combined organic layers were dried on Na₂SO₄, concentrated invacuo and the residue was purified by silica gel column chromatographyto furnish a mixture of cis and trans stereoisomers in a ratio of 2to 1. A second silica gel column chromatography purification (DCM/MeOH,9/1, v/v) resulted in the isolation of two enriched stereoisomerfractions. Compound 307-cis (Rf, 0.2, 0.46 g, 51%, cis/trans=95/5) and306-trans (Rf 0.25, 0.21 g, 25%, cis/trans=5/95). 307-cis: ¹H NMR (400MHz, DMSO-d₆): □ ppm 1.92-2.05 (m, 2H); 2.26-2.37 (m, 2H); 2.68 (t,J=4.5 Hz, 2H); 2.70-2.79 (m, 3H); 2.89-3.00 (m, 1H); 3.30-3.41 (bs, 2H);5.21 (s, 2H) 7.14 (d, J=8.8 Hz, 2H); 7.41 (d, J=8.5 Hz, 2H); 7.61 (d,J=8.5 Hz, 2H); 7.87 (d, J=8.8 Hz, 2H); 12.15 (br. s., 1H); 306-trans: ¹HNMR (400 MHz, DMSO-d₆) □ ppm: 2.10-2.21 (m, 2H); 2.22-2.34 (m, 2H); 2.67(t, J=4.8 Hz, 2H); 2.71-278 (m., 2H); 2.84-2.95 (m, J=9.6 Hz, 1H); 3.17(quin, J=7.4 Hz, 1H); 3.31-3.40 (bs, 2H); 5.21 (s, 2H); 7.14 (d, J=8.8Hz, 2H); 7.41 (d, J=8.5 Hz, 2H); 7.61 (d, J=8.5 Hz, 2H); 7.87 (d, J=8.8Hz, 2H); 12.20 (br. s., 1H). LC-MS Rt 1.41, [M+H]=489.

3-{2-[4-(3,4-Difluorobenzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-cyclobutanecarboxylic acid (277)

Compounds 278-cis and 277-trans were prepared as described for 306.278-cis: ¹H NMR (400 MHz, DMSO-d₆): □ ppm 1.93-2.04 (m, 2H) 2.26-2.36(m, 2H) 2.68 (t, J=4.8 Hz, 2H) 2.70-2.80 (m, 3H) 2.88-3.00 (m, 1H)3.33-3.40 (bs, 2H) 5.16 (s, 2H) 7.14 (d, J=8.8 Hz, 2H) 7.29-7.38 (m, 1H)7.47 (dt, J=10.7, 8.4 Hz, 1H) 7.56 (ddd, J=11.5, 8.0, 2.0 Hz, 1H) 7.87(d, J=8.8 Hz, 2H) 12.15 (br. s., 1H); LC-MS (method A): Rt 1.33,[M+H]=441; 277-trans: ¹H NMR (400 MHz, DMSO-d₆): □ ppm 2.09-2.20 (m, 2H)2.23-2.31 (m, 2H) 2.67 (t, J=4.5 Hz, 2H) 2.70-2.77 (m, 2H) 2.84-2.93 (m,1H) 3.12-3.22 (m, 1H) 3.32-3.39 (bs, 2H) 5.16 (s, 2H) 7.14 (d, J=8.8 Hz,2H) 7.30-7.37 (m, 1H) 7.47 (dt, J=10.8, 8.4 Hz, 1H) 7.56 (ddd, J=11.4,8.0, 1.9 Hz, 1H) 7.87 (d, J=8.8 Hz, 2H) 12.20 (br. s., 1H); LC-MS(method A): Rt 1.31, [M+H]=441.

3-Bromo-N-benzyloxycarbonyl-4-piperidone (502)

To a cooled (0° C.) solution of N-benzyloxycarbonyl-4-piperidone (501,27.3 g 117 mmol) in DCM (3 ml/mmol) was added DIPEA (25.5 ml, 146.2mmol, 1.25 eg) and trimethylsilyl trifluoromethane sulfonate (25.4 ml,141 mmol, 1.2 eg). The mixture was stirred for 30 minutes at 0° C. Next,N-bromosuccinimide (21.2 g, 119.3 mml, 1.02 eg) was added and stirringwas continued for 16 hrs at room temperature. The reaction mixture waswashed with 5% NaHCO₃ and the organic layer was dried (MgSO₄) andsubsequently concentrated under reduced pressure. The resulting oil waspurified by silica gel chromatography (diethyl ether/petroleum ether,1/1 to 1/0, v/v, Rf 0.1) giving 502 in a yield of 90% as a yellow oil.

2-(4-Methoxy-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylicacid benzyl ester (504)

Compound 502 (2.0 g, 6.5 mmol) was dissolved in ethanol (20 ml). To thesolution was added 4-methoxythiobenzamide (503, 1.09 g, 6.5 mmol, 1 eq)and the yellow mixture was refluxed for 17 hrs after which time TLCanalysis showed full conversion of 502. The reaction mixture wasconcentrated in vacuo and the residue was dissolved in EtOAc, washedwith 5% Na₂SO₄ and the organic layer was dried (MgSO₄) and subsequentlyconcentrated under reduced pressure. The resulting oil was purified bysilica gel chromatography (diethyl ether, Rf 0.3) giving compound 504 ina yield of 49% as a colorless oil. Compounds having a Rb substitute canbe prepared by choosing a properly substituted(Rb)-4-methoxythiobenzamide (503).

4-(4,5,6,7-Tetrahydro-thiazolo[5,4-c]pyridine-2-yl)-phenol 505

Compound 504 (18.0 g, 47.3 mmol) was dissolved in ethanol (300 ml). Tothe cooled (−78° C.) solution was added boron tribromide (5 eg, 236mmol) dropwise. After one hour cooling was removed and the mixture wasstirred 16 hrs at room temperature. The reaction was quenched with MeOH,the mixture was concentrated in vacuo to give compound 505 as an oilwhich was used in the next step without further purification.

General Procedure for the Synthesis of Compounds 508.

Compounds 508 are prepared starting from compounds 505 in a similarfashion as described for the synthesis of compounds 7 and 21 (seeschemes 1-4). As a typical example we describe the synthesis of compound508 (Ra=F, Rb=H, Rc=C2).

3-[2-(4-(Hydroxy-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-yl]-propionicacid t-butyl ester (506, Rb=H, Rc=C2)

To a suspension of 505 (Rb=H, 5.8 g, 25.1 mmol) in MeOH (100 ml) andDIPEA (5.1 ml, 30.1 mmol, 1.2 eq) was added t-butyl acrylate (4.4 ml,30.1 mmol, 1.2 eq) and the mixture was refluxed for 16 hrs after whichtime TLC analysis (diethyl ether, Rf 0.2) showed full conversion of 505.The reaction mixture was concentrated in vacuo and the residue wasdissolved in EtOAc, washed with 5% NaHCO₃ and the organic layer wasdried (Na₂SO₄) and subsequently concentrated under reduced pressure. Theresulting oil was purified by silica gel chromatography (diethyl ether)giving compound 506 (Rb=H, Rc=C2) in a yield of 79% as a white solidmaterial.

3-[2-(4-(2-Fluoro-benzyloxy)-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-yl]-propionicacid t-butyl ester (507, Ra=2F, Rb=H, Rc=C2)

To a suspension of 506 (Rb=H, Rc=C2, 0.5 g, 1.4 mmol) in DMA (4 ml) wasadded triphenyl phosphine (0.45 g, 1.7 mmol, 1.25 eg), diisopropylazodicarboxylate (0.33 ml, 1.7 mmol, 1.25 eq) and 2-fluoro benzylalcohol (0.17 ml, 1.56 mmol, 1.15 eg) and the mixture was stirred atroom temperature for 16 hrs. The reaction mixture was diethyl ether (150ml) and washed with 3×50 ml water. The combined organic layers weredried (Na₂SO₄) and subsequently concentrated under reduced pressure. Theresulting oil was purified by silica gel chromatography (diethylether/petroleum ether, 2/1, v/v) giving compound 507 (Ra=2F, Rb=H,Rc=C2) in a yield of 67% as a white solid material.

3-[2-(4-(2-Fluoro-benzyloxy)-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-yl]-propionicacid (38, Ra=2F, Rb=H, Rc=C2)

Compound 507, Ra=2F, Rb=H, Rc=C2, 0.43 g, 0.9 mmol) was dissolved in 4NHCl in dioxane (10 ml). The mixture was stirred for 16 hrs at roomtemperature. The mixture was concentrated in vacuo and the resultingsolid was washed with diisopropyl ether to give 38 as a white solid(Ra=2F, Rb=H, Rc=C2, 0.42 g, 97%). Compound 38: ¹H NMR (400 MHz,DMSO-d₆), □ ppm 2.88-3.03 (m, 2H), 3.06-3.14 (m, 1H), 3.20 (m, 1H), 3.48(broad signal, 3H), 3.73-3.87 (m, 1H), 4.44 (bd, J=15.9, 6.0 Hz, 1H),4.72 (b, J=15.9 Hz, 1H), 5.22 (s, 2H), 7.16 (d, J=8.6 Hz, 2H), 7.23-7.32(m, 2H), 7.41-7.49 (m, 1H), 7.59 (dt, J=7.6, 1.5 Hz, 1H), 7.87 (d, J=8.6Hz, 2H), 11.63 (br. s., 1H); LC-MS (Method A): Rt 1.3, [M+H] 473.

4-Bromo-N-(4-chloro-pyridin-3-yl)-benzamide (510)

A mixture of 4-amino-3-chloropyridine (509, 5.9 g, 46.2 mmol),4-bromobenzoyl chloride (15, 11.15 g, 50.8 mmol) and potassium carbonate(22.4 g, 161.7 mmol) in acetonitril (150 ml) was refluxed for 24 hrs.The reaction mixture was concentrated in vacuo, redissolved in DCM andthe solution was washed with water. The organic layer was dried (MgSO₄),concentrated and the resulting oil was purified by silica gel columnchromatography (DCM/MeOH, 99/1, v/v, Rf 0.2) to give pure 510 (10.4 g,72%) as an oil. When a substituted compound 15 is used, the Rb incompound 510 is introduced.

2-(4-Bromo-phenyl)-thiazolo-[4,5c]-pyridine (511)

Compound 510 (10.4 g, 33.4 mmol) was suspended in toluene (400 ml) andLawesson's reagent (9.4 g, 23.4 mmol, 0.7 eq) was added and the mixturewas refluxed for 24 hrs after which time TLC analysis (DCM/MeOH, 97/3,v/v, Rf 0.7) revealed the reaction to be complete. The mixture wasconcentrated in vacuo and to the oil was added NaHCO₃ (5% solution, 200ml) and the suspension was extracted with DCM (3×200 ml). The combinedorganic layers was dried over MgSO₄, concentrated and the oil waspurified by silica gel column chromatography (DCM/MeOH, 99/1 to 97/3,v/v) to give pure 511 (8.7 g, 89%) as an oil.

2-(4-Benzyloxy-phenyl)-4,5,6,7-tetrahydro-thiazolo-[4,5c]-pyridine (518)

Compounds 518 were obtained starting from 511 in a similar fashion asdescribed for the synthesis of compounds 27 in schemes 4 and 7. Theappropriate tails Rc could be linked to 518 in a similar fashion asdescribed for compounds 27.

4-{2-[4-(3,5-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-thiazolo-[4,5c]-pyridin-5-yl}-butyricacid (446, Ra=3,5-F, Rb=H, Rc=C3)

Compound 519 (Ra=3,5-F, Rb=H, Rc=C3, 0.79 g, 1.58 mmol) was dissolved in4N HCl in dioxan (25 ml) was stirred for 18 hrs at 50° C. and for 70 hrsat room temperature. The mixture was concentrated in vacuo and theresulting oil was stirred in diethyl ether to yield 446 as a white solid(0.72 g, 94%). ¹H NMR (400 MHz, DMSO-d₆): □ ppm: 2.03-2.15 (m, 2H), 2.40(t, J=7.3 Hz, 2H), 3.12-3.22 (m, 1H), 3.32 (broad signal, 3H), 3.40-3.51(m, 1H), 3.75-3.90 (m, 1H), 4.36 (dd, J=15.2, 6.8 Hz, 1H), 4.59 (d,J=15.2 Hz, 1H), 5.21 (s, 2H), 7.05 (tt, J=9.0, 2.3 Hz, 1H), 7.09-7.18(m, 4H), 7.84 (d, J=8.9 Hz, 2H), 11.17 (br. s., 1H); Rt 1.33, [M+H] 502.

2-{2-[4-(3,5-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-aceticacid (463)

2-[4-(3,5-difluoro-benzyloxy)-phenyl]-4,5,6,7-tetrahydro-oxazolo[4,5-c]pyridine(27, Ra=3,5-diF, Rb=H) was synthesized following route C as describedabove. Compound 27 (Ra=3,5-diF, Rb=H, 0.4 g, 1.17 mmol) was dissolved inacetonitril (20 ml). To the solution was added DIPEA (0.51 ml, 2.9 mmol,2.5 eq) and t-butyl bromoacetate (0.19 ml, 1.29 mmol, 1.1 eq). Themixture was refluxed for 6 hrs after which time LCMS analysis showed thereaction to be complete. The mixture was concentrated in vacuo, waterwas added and the suspension was extracted with DCM (3×200 ml). Thecombined organic layers was dried over MgSO₄, concentrated and the oilwas purified by silica gel column chromatography (diethylether/petroleum ether, 3/1, v/v). The resulting oil was suspended in 4NHCl in dioxan (20 ml). The mixture was stirred at 45° C. for 5 hrs andat room temperature for 16 hrs. The mixture was concentrated in vacuo togive a white solid. The solid material was washed 3 times with diethylether to give 463 (0.39 g, 91%) as a white solid. ¹H NMR (400 MHz,DMSO-d₆): □ ppm: 3.10-3.20 (m., 2H), 3.70-3.80 (m., 2H), 4.31 (s, 2H),4.44 (s, 2H), 5.22 (s, 2H), 7.02-7.10 (m, 1H), 7.13-7.20 (m, 4H), 7.92(d, J=8.8 Hz, 2H), 9.53-12.44 (br.s., 1H); Rt 1.51; [M+H] 401.

2-{2-[4-(3,5-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-propionicacid (464)

Compound 27 (Ra=3,5-diF, Rb=H, 0.4 g, 1.17 mmol) was dissolved inacetonitril (20 ml). To the solution was added DIPEA (0.51 ml, 2.9 mmol,2.5 eq) and t-butyl 2-bromo-propionic ester (0.27 gl, 1.29 mmol, 1.1eq). The mixture was refluxed for 24 hrs after which time LCMS analysisshowed the reaction to be complete. The mixture was concentrated invacuo, water was added and the suspension was extracted with DCM (3×200ml). The combined organic layers were dried on MgSO₄, concentrated andthe oil was purified by silica gel column chromatography (diethylether/petroleum ether, 3/2, v/v, Rf 0.3). The resulting oil wassuspended in 4N HCl in dioxan (20 ml). The mixture was stirred at 45° C.for 5 hrs and at room temperature for 16 hrs. The mixture wasconcentrated in vacuo to give a white solid. The solid material waswashed 3 times with diethyl ether to give 464 (0.41 g, 89%) as a whitesolid. ¹H NMR (400 MHz, DMSO-d₆): □ ppm, 1.66 (d, J=7.1 Hz, 3H), 3.17(br. s., 2H), 3.74 (br. s., 2H), 4.33-4.52 (m, 4H), 5.22 (s, 2H),7.02-7.11 (m, 1H), 7.13-7.25 (m, 4H), 7.92 (d, J=8.8 Hz, 2H); Rt 1.53,[M+H] 415.

3-{2-[4-(3,5-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-oxazolo[4,5-c]-pyridin-5-yl}-cyclopentanecarboxylic acid (465, 1/1 cis-trans mixture)

Compound 27 (Ra=3,5-diF, Rb=H, 0.1 g, 0.29 mmol) was dissolved in1,2-dichloroethane (5 ml). To the solution was added3-oxo-cyclopentane-carboxylic acid (0.05 g, 0.41 mmol, 1.4 eq), sodiumtriacetoxy borohydride (0.11 g, 0.53 mmol, 1.8 eq) and AcOH (0.03 ml,0.58 mmol, 2 eq). The mixture was stirred for 16 hrs after which timeLCMS analysis showed the reaction to be complete. To the mixture wasadded a saturated solution of NH₄Cl and the mixture was extracted withDCM. The combined organic layers was concentrated in vacuo and the oilwas purified by silica gel column chromatography (DCM/MeOH, 9/1, v/v) togive compound 465 as a cis/trans mixture in a ratio of 1/1.

Rt 1.27, [M+H] 455.

4-{2-[4-(2,3-Difluoro-benzyloxy)-2-methyl-phenyl]-6,7-dihydro-4H-oxazolo-[4,5c]-pyridin-5-yl}-pentanoicacid (393)

Compound 22 (Rb=2Me, Rc=H) was prepared by stirring 29 (Rb=2Me) in amixture of TFA and DCM for 16 hrs. The solvents were evaporated to givecrude 22 (Rb=2Me, Rc=H) as an oil which was used in the next stepwithout further purification. A SCX-2 column was used to make the freebase of compound 22 (Rb=2Me, Rc=H, 1 g, 4.3 mmol), which was dissolvedin MeOH. To this solution was added ethyl levulinate (2.46 ml, 17.4mmol, 4 eq), AcOH (0.5 ml, 8.7 mmol, 2 eq) and palladium hydroxide oncarbon. The reaction mixture was shaken at a pressure of 4 atm ofhydrogen. After 16 hrs, ELSD showed that the reaction was not yetcomplete. Another portion of ethyl levulinate (2.46 ml, 17.4 mmol, 4 eq)and palladium hydroxide on carbon was added and hydrogenation at 4 atmwas continued for 72 hrs. The mixture was degassed, filtered over Hyfloand the residue was washed with MeOH. The filtrate was concentrated invacuo and the resulting oil was purified by silica gel columnchromatography to give 522 (Rb=2Me, Rc=xCH₂(CH₃)CH₂CH₂C(═O)OEt) in anyield of 41%. Subsequent benzylation of 522 with 2,3-di-fluoro-benzylbromide was performed in a similar fashion as described for thecompounds of Schemes 1-5 giving compound 523. Finally, the latter wasdissolved in a solution of sodium hydroxide in ethanol (18 ml, 0.3M) andthe solution was stirred at 50° C. for 16 hrs. The mixture wasconcentrated in vacuo and the residue was stirred in diethyl ether togive 393 as a white solid (Ra=2,3-diF, Rb=2Me,Rc=CH₂(CH₃)CH₂CH₂C(═O)OH). ¹H NMR (400 MHz, DMSO-d₆): □ ppm 1.40 (d,J=5.9 Hz, 3H), 1.74-1.93 (m, 1H), 2.15-2.30 (m, 1H), 2.31-2.50 (m, 3H),2.63 (s, 3H), 3.04-3.15 (m, 1H), 3.22-3.35 (m, 1H), 3.45-3.69 (m, 2H),3.72-3.85 (m, 1H), 4.22-4.46 (m, 2H), 5.25 (s, 2H), 6.98-7.07 (m, 2H),7.20-7.29 (m, 1H), 7.34-7.45 (m, 2H), 7.87 (d, J=8.6 Hz, 1H),10.49-10.69 (br.band, 1H), 11.47-13.29 (br.band, 1H). Rt 1.37, [M+H]457.

4-{2-[4-(2,3-Difluoro-benzyloxy)-2-methyl-phenyl]-6,7-dihydro-4H-oxazolo[4,5-c]-pyridin-5-yl}-2-methyl-butyricacid (394)

Compound 22 (Rb=2Me, 1 g, 3.8 mmol) was dissolved in acetonitril (10 ml)and to the solution was added DIPEA (1.93 ml, 11.25 mmol), sodium iodide(0.56 g, 3.75 mmol) and 4-chloro-2-methylbutyric acid methyl ester (0.85g, 5.6 mmol). The mixture was stirred at 60° C. for 16 hrs, after whichtime again added DIPEA (1.93 ml, 11.25 mmol), sodium iodide (0.56 g,3.75 mmol) and 4-chloro-2-methylbutyric acid methyl ester (0.85 g, 5.6mmol) were added and stirring was continued for 30 hrs at 60° C. Themixture was concentrated in vacuo and purified by silica gel columnchromatography (DCM/MeOH, 95/5 to 9/1, v/v) to give 525 (Rb=2Me; Rd=Me)as an oil. Compound 525 (Rb=2Me; Rd=Me) was benzylated at Mitsunobuconditions in a similar fashion as described above for the synthesis of23. The resulting compounds 526 (0.5 mmol) were dissolved in ethanol (20ml) and 2N NaOH solution was added (4 ml) and the mixture was stirredfor 2 hrs at 50° C. The solution was neutralized with 1M HCl, extractedwith DCM (3×20 ml) and the organic layers were dried on MgSO₄.Evaporation of the solvent resulted in the isolation of pure compound394. ¹H NMR (400 MHz, DMSO-d₆): □ ppm 1.09 (d, J=7.1 Hz, 3H), 1.51-1.61(m, 1H), 1.80-1.92 (m, 1H), 2.36-2.46 (m, 1H), 2.56 (t, J=7.1 Hz, 2H),2.60 (s, 3H), 2.72-2.78 (m, 2H), 2.79-2.85 (m, 2H), 3.39-3.47 (m, 2H),5.24 (s, 2H), 6.95-7.04 (m, 2H), 7.20-7.29 (m, 1H), 7.35-7.47 (m, 2H),7.82 (d, J=8.6 Hz, 1H), 10.85-13.06 (br.band, 1H). LC-MS: Rt 1.38, [M+H]457.

4-{2-[4-(2,3-Difluoro-benzyloxy)-2-methyl-phenyl]-6,7-dihydro-4H-oxazolo-[4,5c]-pyridin-5-yl}-3-methyl-butyricacid (437) Synthesis of 4-Chloro-3-methyl-butyric acid methyl ester

4-Methyl-dihydro-furan-2-one (4 g, 39.95 mmol) was dissolved in MeOH (10ml) and the solution was cooled to −10° C. Thionyl chloride (3.6 ml,49.9 mmol) was added dropwise. The mixture was stirred at −10° C. for 2hrs and hereafter for 16 hrs at room temperature. The mixture wasconcentrated in vacuo to give crude 4-Chloro-3-methyl-butyric acidmethyl ester (4 g, 87%) which was used in the next step without furtherpurification.

Compound 22 (Rb=2Me, Rd=Me) was selectively alkylated at the nitrogenposition with 4-chloro-3-methyl-butyric acid methyl ester to give 528.Subsequent benzylation of 528 under previously described Mitsunobuconditions gave 529. Compound 529 was demethylated in a similar fashionas described above for the synthesis of compound 394 to give compound437 (Ra=2,3-diF, Rb=2Me, Rd=H) as a white solid. ¹H NMR (400 MHz,DMSO-d₆): □ ppm 1.12 (d, J=6.6 Hz, 3H), 2.26 (dd, J=16.3, 7.3 Hz, 1H),2.44-2.57 (m, 2H), 2.63 (s, 3H), 2.99-3.96 (m, 6H), 4.10-4.65 (br. b.,2H), 5.24 (s, 2H), 6.96-7.08 (m, 2H), 7.18-7.27 (m, 1H), 7.31-7.43 (m,2H), 7.88 (d, J=8.6 Hz, 1H), 10.17-11.21 (br.band, 1H), 11.46-13.30(br.band, 1H). LC-MS: Rt 1.44, [M+H] 457.

3-{2-[4-(2-phenyl-cyclopropyl)-3-fluoro-phenyl]-6,7-dihydro-4H-oxazolo-[4,5-c]-pyridin-5-yl}-cyclobutanecarboxylic acid (459 trans)

2-Phenyl-cyclopropyl-trifluoroborane.4,4,5,5-Tetramethyl-2-(2-phenyl-cyclopropyl)-[1,3,2]dioxaborolane (3.1g, 12.7 mmol) in MeOH (48 ml) and water (12 ml) was cooled to 0° C.Potassium bifluoride (6.96 g, 88.9 mmol, 7 eq) was added and the mixturewas stirred for 16 hrs at room temperature. The mixture was concentratedin vacuo and the residue was co-evaporated with acetonitril (3×40 ml).The residue was washed with warm acetonitril (3×40 ml) and the combinedactonitril washings were concentrated to give2-phenyl-cyclopropyl-trifluoroborane (2 g, 71%). This trifluoroboranederivative (1.8 g, 8.2 mmol, 1.3 mmol) was dissolved in degassedtoluene/water (137.5 ml, 10/1, v/v) and potassium phosphate tribasic(5.2 g, 24.7 mmol, 3.9 eq) was added. The mixture was stirred for 15minutes and to this solution was added compound 28 (Rb=3F, 2.5 g, 6.3mmol), palladium(II) acetate (71.2 mg, 0.3 mmol, 0.05 eq) and2-dicyclohexylphosphino-2,6-di-isopropoxy-1,1-biphenyl (296 mg, 0.6mmol, 0.1 eq, RuPhos). The mixture was stirred at 115° C. for 3 hrsafter which time TLC analysis (Et₂O/PA, 3/7, v/v) revealed the reactionto be complete. The mixture was allowed to reach room temperature andwas diluted with EtOAc (300 ml) and the solution was washed with water.The organic layer was dried on MgSO₄ and concentrated in vacuo to givean oil which was purified by silica gel column chromatography (Et₂O/PA,3/7, v/v) to give pure 530 (2.54 g, 92%) as a white solid. The BOC in530 was removed under acidic conditions to give 531, which wastransformed to 532 under conditions for introducing the Rc-tail asdescribed above. Compound 532 (pure trans, 0.45 g, 0.94 mmol) wasdissolved in 20 ml 4M HCl in dioxan. The solution was stirred for 16 hrsat room temperature. The mixture was concentrated in vacuo and stirredin diethyl ether. The resulting solid was filtered to give compound 459(trans, 0.36 g, 83%). ¹H NMR (400 MHz, DMSO-d₆): □ ppm 1.27 (d, J=7.3Hz, 3H), 1.51-1.70 (m, 2H), 2.26-2.40 (m, 2H), 3.05-3.23 (m, 3H), 3.27(dd, J=13.1, 4.8 Hz, 2H), 3.55-3.84 (m, 3H), 4.37 (br. s., 2H),7.14-7.23 (m, 3H), 7.26-7.35 (m, 3H), 7.64 (d, J=11.1, Hz, 1H), 7.74 (d,J=8.3 Hz, 1H), 10.00-11.79 (br.band, 1H), 11.93-13.53 (br.band, 1H).LC-MS: Rt 1.36, [M+H] 433.

4-(2-{4-[2-(3,5-Difluoro-phenyl)-vinyl]-phenyl}-6,7-dihydro-4H-oxazolo-[4,5c]-pyridin-5-yl)-butyricacid (451)

A solution of compound 28 (Rb=H, 4.3 g, 11.1 mmol),trans-2-(3,5-difluorophenyl)vinyl boronic acid pinacol ester (4.09 ml,16.7 mmol, 1.5 eq) in toluene (100 ml) was degassed. To this solutionwas addedchloro(2-dicyclohexylphosphino-2,4,6-tri-isopropopyl-1,1-biphenyl)[2-(2-aminoethyl)pentyl]palladium(II)methyl-tbutyl ether adduct (183.8 mg, 0.22 mmol, 0.02 eq) and potassiumphosphate tribasic (7.08 g, 33.3 mmol, 3.0 eq) was added. The mixturewas stirred for 24 hrs at 115° C. after which time LC-MS analysisrevealed the reaction to be complete. The mixture was allowed to reachroom temperature and was diluted with EtOAc (300 ml) and the solutionwas washed with a 5% NaHCO₃ solution. The organic layer was dried onMgSO₄ and concentrated in vacuo to give an oil which was purified bysilica gel column chromatography (DCM/MeOH, 99.5/0.5, v/v) to give pure533 (3.4 g, 69%) as a white solid. The BOC in 533 was removed underacidic conditions to give 534, which was transformed to 535 underconditions for introducing the Rc-tail as described above. Compound 535(0.45 g, 0.94 mmol) was dissolved in 20 ml 4M HCl in dioxan. Thesolution was stirred for 16 hrs at 55° C. The mixture was concentratedin vacuo and stirred in diethyl ether. The resulting solid was filteredto give compound 451 (0.426 g, 95%).

¹H NMR (400 MHz, DMSO-d₆) □ ppm 2.02-2.14 (m, 2H) 2.40 (t, J=7.1 Hz, 2H)3.07-3.18 (m, 1H) 3.23-3.38 (m, 3H) 3.65-3.72 (m, 1H) 3.78-3.89 (m, 1H)4.23-4.35 (m, 1H) 4.41-4.54 (m, 1H) 6.96-7.05 (m, 1H) 7.28-7.37 (m, 3H)7.41 (d, J=16.4 Hz, 1H) 7.74 (d, J=8.3 Hz, 2H) 7.98 (d, J=8.3 Hz, 2H)11.25 (br. s., 1H). LC-MS: Rt 1.39, [M+H] 425.

4-(2-{4-[2-(3,5-Difluoro-phenyl)-ethyl]-phenyl}-6,7-dihydro-4H-oxazolo[4,5c]pyridin-5-yl)-butyricacid (452)

Compound 533 (1.5 g, 3.4 mmol) was dissolved in MeOH (250 ml). To thesuspension was added palladium hydroxide on carbon (20%, 0.2 g, 1.42mmol, 0.42 eq). The mixture was placed under a blanket of hydrogen atroom temperature and 1 atmosphere. After 24 hrs, LC-MS analysis revealedthe reaction to be complete (TLC analysis: DCM/MeOH, 99/1, v/v). Themixture was filtered over Hyflo and the filtrate was concentrated invacuo to give 536 (1.43 g, 95%) as an oil. Compound 536 was converted tothe corresponding tail derivative 538 as described above. The tBu ormethyl esters were deprotected in a similar fashion as described above.Compound 452: ¹H NMR (400 MHz, DMSO-d₆) □ ppm 1.99-2.13 (m, 2H) 2.39 (t,J=7.2 Hz, 2H) 2.96 (s, 4H) 3.18 (broad band, 2H) 3.25-3.33 (m, 2H)3.51-3.95 (broad band, 2H) 4.34 (br. s., 2H) 6.85-6.98 (m, 3H) 7.37 (d,J=8.3 Hz, 2H) 7.88 (d, J=8.3 Hz, 2H) 10.67-11.61 (broad band, 1H)11.86-12.71 (broad band, 1H). LC-MS: Rt 1.36, [M+H] 427.

Preparation of the Pure Enantiomers of Chiral Compounds 1 and 2.

Compounds having for example a methyl substitution in the Rc-tail givemixtures of enantiomers as the test compound. Separation of this mixturein the pure enantiomers can be performed by chiral HPLC techniques fromthe moment that the chiral tail is introduced in the core, i.e. of forexample compounds 1, 2, 7, 8, 9, 21, 22, 23. For those skilled in theart, it is obvious that small changes in the core can lead to adifferent behavior in the chiral separation process. Therefore, eachcompound has been screened using a broad set of conditions such aschiral column material and eluents. In that way, for each compound wasdetermined in which stage and under which chiral separation conditionsthe separation would be most successful. The separated end products werenamed as Rel1 and Rel2 as the absolute configuration was not yetdetermined. This process is illustrated by the following typicalexamples.

3-[2-(4-Hydroxy-phenyl)-4,5,6,7-tetrahydro-oxazolo[4,5-c]pyridine]-2-methyl-propionicacid t-butyl ester (+) and (−) enantiomers of 22b (Rb=H)

Compound 22b was made as an enantiomeric mixture as described in Scheme5. Enantiomeric mixture was separated by chiral HPLC using the followingchiral HPLC system. Stationary phase: Chiralcel OD-H (5 micron); mobilephase: n-heptane/2-propanol (90/10, v/v) +0.1% TFA; flowrate 1 ml/min;detection by UV at 280 nm. Compound 22b-rel1: [α]²⁵=+37.1; ¹H NMR (400MHz, Chloroform-d) □ ppm 1.14 (d, J=6.8 Hz, 3H) 1.43 (s, 9H) 2.54 (dd,J=12.1, 6.2 Hz, 1H) 2.60-2.70 (m, 1H) 2.73-2.77 (m, 2H) 2.80-2.97 (m,3H) 3.49 (d, J=14.1 Hz, 1H) 3.60 (d, J=14.1 Hz, 1H) 6.71-6.96 (br.band,1H) 6.84 (d, J=8.6 Hz, 2H) 7.82 (d, J=8.6 Hz, 2H). Compound 22-rel2:[α]²⁵=−35.9; ¹H NMR (400 MHz, Chloroform-d) □ ppm 1.14 (d, J=6.8 Hz, 3H)1.42 (s, 9H) 2.53 (dd, J=12.4, 6.2 Hz, 1H) 2.60-2.70 (m, 1H) 2.72-2.79(m, 2H) 2.80-2.96 (m, 3H) 3.49 (d, J=14.1 Hz, 1H) 3.59 (d, J=14.1 Hz,1H) 6.83 (d, J=8.6 Hz, 2H) 7.45-7.75 (br.band, 1H) 7.79 (d, J=8.6 Hz,2H).

3-[2-(4-hydroxy-3-F-phenyl)-4,5,6,7-tetrahydro-oxazolo[4,5-c]pyridine]-2-methyl-propionicacid t-butyl ester (+) and (−) enantiomers of 22b (Rb=3F)

Compound 22b (Rb=H) was made as an enantiomeric mixture as described inScheme 5. Enantiomeric mixture was separated by chiral HPLC using thefollowing chiral HPLC system. Stationary phase: Chiralcel OD-H (5micron); mobile phase: n-heptane/2-propanol (90/10, v/v) +0.1% TFA;flowrate 1 ml/min; detection by UV at 280 nm. Compound 22b-rel1:[α]²⁵=−36.4 (MeOH). Compound 22-rel2: [α]²⁵=+34.8; ¹H NMR (400 MHz,Chloroform-d) □ ppm 1.15 (d, J=6.8 Hz, 3H) 1.43 (s, 9H) 2.54 (dd,J=11.9, 6.2 Hz, 1H) 2.60-2.71 (m, 1H) 2.73-2.79 (m, 2H) 2.81-2.96 (m,3H) 3.49 (d, J=14.1 Hz, 1H) 3.59 (d, J=14.1 Hz, 1H) 4.88-6.89 (br.band,1H) 7.02 (t, J=8.5 Hz, 1H) 7.61-7.73 (m, 2H).

3-{2-[4-(2,3-difluoro-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid rel 1 and rel 2 of compound 175

The tbutylprotected derivative of 175 was separated in its pureenantiomers by chiral HPLC. Stationary phase: Chiralpak IC (5μ); columncode no.: WJH022830; dimensions: 250×4.6 mm; Mobile phase:n-Heptane/DCM/ethanol (50/50/1)+0.1% DEA; flowrate: 1 ml/min; Injection:5 μl; Detection: UV (290 nm). Deprotection of thus obtained pureenantiomers resulted in the isolation of the test compounds 426 and 425.Compound 426, rel1: [α]²⁵=−22 (MeOH), Rt 1.3, [M+H] 429. Compound 425rel2: [α]²⁵=+19.9 (MeOH); Rt 1.3, [M+H] 429.

TABLE 1

A

B

C

D

E RT (min) No. R1 Z R2 X Y R3 Structure R4 LC-MS  31 4Cl-phenyl CH₂N H CO H B —(CH₂)₂—COOH 1.37  32 cyclohexyl CH₂O H C O H B —(CH₂)₃—COOH 1.46 33 2F-phenyl CH₂O H C O H B —(CH₂)₂—COOH 1.39  34 2,6diCl-phenyl CH₂O HC O H B —(CH₂)₃—COOH 1.4  35 2F-phenyl CH₂O H C O H B —(CH₂)₃—COOH 1.37 36 2F-3pyridyl CH₂O H C O H B —(CH₂)₂—COOH 1.21  37 phenyl CH₂ H C O HB —(CH₂)₂—COOH 1.38  38 2F-phenyl CH₂O H N S D —(CH₂)₂—COOH 1.3  39phenyl N H C O H B —(CH₂)₂—COOH 1.31  40 2,6diCl-phenyl CH₂O H N S D—(CH₂)₃—COOH 1.35  41 phenyl C═C H C O H B —(CH₂)₂—COOH 1.42 HC═CH  42phenyl (CH₂)₂ H C O H B —(CH₂)₂—COOH 1.45  43 phenyl SO₂ H C O H B—(CH₂)₂—COOH #  44 phenyl S H C O H B —(CH₂)₂—COOH 1.43  45 benzyl S H CO H B —(CH₂)₂—COOH 1.41  46 phenyl O H C O H B —(CH₂)₂—COOH 1.37  47phenyl CH₂O H N O B —(CH₂)₂—COOH 1.32  48 2F-phenyl CH₂O 2Cl C O H B—(CH₂)₂—COOH 1.43  49 phenyl CH₂SO₂ H C O H B —(CH₂)₂—COOH 1.16  50phenyl CH₂O 3-pyr C O H B —(CH₂)₂—COOH 1.27  51 2F-phenyl CH₂O 3F C O HB —(CH₂)₂—COOH 1.34  52 phenyl C═O H C O H B —(CH₂)₂—COOH 1.23  53phenyl CH₂O H N O B —(CH₂)₃—COOH 1.17  54 2F-phenyl CH₂O H N O B—(CH₂)₂—COOH 1.18  55 2,3-diF-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.19  562F-phenyl CH₂O H N O B —(CH₂)₃—COOH 1.15  57 2,3-diF-phenyl CH₂O H N O B—(CH₂)₃—COOH 1.16  58 4Cl-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.37  592F-phenyl CH(Me)—O H C O H B —(CH₂)₃—COOH #  60 2,6-diCl-phenyl CH₂O H NO B —(CH₂)₃—COOH 1.32  61 4Cl-phenyl CH₂O H N O B —(CH₂)₃—COOH 1.29  622,6-diCl-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.36  63 2F-phenyl NH H C O HE —(CH₂)₂—COOH 1.33  64 2F-phenyl CH₂O H C O H A —(CH₂)₂—COOH 1.32  652F-phenyl bond H C O H E —(CH₂)₂—COOH 1.33  66 2F-phenyl O H C O H E—(CH₂)₂—COOH 1.34  67 2F-phenyl CH₂O H C O H E —(CH₂)₂—COOH 1.36  682F-phenyl CH₂N H C O H E —(CH₂)₂—COOH 1.29  69 2F-phenyl CH₂O H C O CH₃B —(CH₂)₂—COOH 1.38  70 2F-phenyl CH₂O H C O H C —(CH₂)₂—COOH 1.35  712F-phenyl CH₂O H C O H A —(CH₂)₂—COOH 1.32  72 2F-phenyl CH₂O H C O H D—(CH₂)₂—COOH 1.36  73 2F-phenyl CH₂O 2F C O H B —(CH₂)₃—COOH 1.35  744CF₃-phenyl CH₂O H C O H B —(CH₂)₂—COOH #  76 phenyl CH₂O H C O H B—CH(CH₃)—CH₂—COOH 1.46  77 4Cl-phenyl CH₂O H C O H B —CH₂—CH(CH₃)—COOH1.56  79 2F-phenyl cyclopropyl H C O H B —(CH₂)₂—COOH 1.46  80 2F-phenylOCH₂ H C O H B —(CH₂)₂—COOH 1.39  81 phenyl CH₂O 2F N O B —(CH₂)₃—COOH1.54  82 phenyl C≡C H C O H E —(CH₂)₂—COOH 1.63  83 2F-phenyl C≡C H C OH E —(CH₂)₂—COOH 1.65  84 3F,5Cl-phenyl CH₂O H C O H B —(CH₂)₂—COOH 1.8 85 4CF₃-phenyl CH₂O 2F N O B —(CH₂)₃—COOH 1.77  86 4Cl-phenyl CH₂O 2F NO B —(CH₂)₃—COOH 1.65  87 2F-phenyl CH₂O 2F N O B —(CH₂)₃—COOH 1.58  882,3-diF-phenyl CH₂O 2F N O B —(CH₂)₃—COOH 1.59  89 2F-phenyl CH₂O 2CH₃ NO B —(CH₂)₃—COOH 1.61  90 phenyl CH₂O 2CH₃ N O B —(CH₂)₃—COOH 1.69  914Cl-phenyl CH₂O 2CH₃ N O B —(CH₂)₃—COOH 1.75  92 2,3-diF-phenyl O 2CH₃ NO B —(CH₂)₃—COOH 1.77  93 3,4-diF-phenyl O 2CH₃ N O B —(CH₂)₃—COOH 1.8 94 4CF₃-phenyl O 2CH₃ N O B —(CH₂)₃—COOH 1.98  95 2CH₃-phenyl O H N O B—(CH₂)₂—COOH 2.09*  96 4CH₃-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.97*  974CH₃O-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.93*  98 4CF₃-phenyl CH₂O H N OB —(CH₂)₂—COOH 2.1*  99 4CF₃O-phenyl CH₂O H N O B —(CH₂)₂—COOH 2.08* 1004F-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.98* 101 3CH₃O-phenyl CH₂O H N O B—(CH₂)₂—COOH 1.86* 102 3F-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.87* 1033CF₃O-phenyl CH₂O H N O B —(CH₂)₂—COOH 2* 104 3CF₃-phenyl CH₂O H N O B—(CH₂)₂—COOH 2.04* 105 2,6diF-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.82* 1062,5diF-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.83* 107 2F,6Cl-phenyl CH₂O H NO B —(CH₂)₂—COOH 1.84* 108 2,3,6triF-phenyl CH₂O H N O B —(CH₂)₂—COOH1.82* 109 3,4diF-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.84* 1102,4diF-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.84* 111 3CH₃-phenyl CH₂O H N OB —(CH₂)₂—COOH 1.86* 112 3,5diF-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.85*113 2CF3-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.88* 114 3,4diF-phenyl CH₂O2F N O B —(CH₂)₃—COOH 1.68 115 2F-phenyl CH₂O 2CH₃ N O B —(CH₂)₂—COOH1.53 116 phenyl CH₂O 2CH₃ N O B —(CH₂)₂—COOH 1.53 117 4Cl-phenyl CH₂O2CH₃ N O B —(CH₂)₂—COOH 1.59 118 2,3diF-phenyl CH₂O 2CH₃ N O B—(CH₂)₂—COOH 1.52 119 3,4diF-phenyl CH₂O 2CH₃ N O B —(CH₂)₂—COOH 1.74120 4CF3-phenyl CH₂O 2CH₃ N O B —(CH₂)₂—COOH 1.8 121 4CH₃-phenyl CH₂O 2FN O B —(CH₂)₂—COOH 1.86* 122 4CF₃-phenyl CH₂O 2F N O B —(CH₂)₂—COOH1.89* 123 4CF₃O-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.93* 124 4F-phenylCH₂O 2F N O B —(CH₂)₂—COOH 1.83* 125 3CH₃O-phenyl CH₂O 2F N O B—(CH₂)₂—COOH 1.82* 126 3F-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.82* 1274Cl-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.88* 128 3CF₃O-phenyl CH₂O 2F N OB —(CH₂)₂—COOH 1.91* 129 2F-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.82* 1303CF₃-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.9* 131 2CH₃-phenyl CH₂O 2F N OB —(CH₂)₂—COOH 1.85* 132 2,6diF-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.8*133 2,5diF-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.84* 134 2F,6Cl-phenylCH₂O 2F N O B —(CH₂)₂—COOH 1.89* 135 2,3,6triF-phenyl CH₂O 2F N O B—(CH₂)₂—COOH 1.84* 136 2,6diCl-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.87*137 2,3diF-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.84* 138 3,4diF-phenylCH₂O 2F N O B —(CH₂)₂—COOH 1.86* 139 2,4diF-phenyl CH₂O 2F N O B—(CH₂)₂—COOH 1.86* 140 2,5diCl-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.91*141 3CH₃-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.86* 142 3,5diF-phenyl CH₂O2F N O B —(CH₂)₂—COOH 1.84* 143 2Cl-phenyl CH₂O 2F N O B —(CH₂)₂—COOH1.9* 144 2CF₃-phenyl CH₂O 2F N O B —(CH₂)₂—COOH 1.89* 145 3,4diCl-phenylCH₂O 2F N O B —(CH₂)₂—COOH 1.95* 146 phenyl CH₂O H N O B—CH₂—CH(CH₃)—COOH 1.48 147 phenyl CH₂O H N O D —(CH₂)₂—COOH 1.28 1483,4diF-phenyl CH₂O 3Me C O B —(CH₂)₃—COOH 1.68 149 4CF₃-phenyl CH₂O H NO B —(CH₂)₃—COOH 1.63 150 2CH₃-phenyl CH₂O H N O B —(CH₂)₃—COOH 1.48 1513,4diF-phenyl CH₂O H N O B —(CH₂)₃—COOH 1.56 152 4F-phenyl CH₂O H N O B—(CH₂)₃—COOH 1.55 153 3,5diF-phenyl CH₂O H N O B —(CH₂)₃—COOH 1.48 1542,3diF-phenyl CH₂O H N O B —CH₂—CH(CH₃)— 1.32 155 3,4diF-phenyl CH₂O H NO B —CH₂—CH(CH₃)— 1.63 156 4CF₃-phenyl CH₂O H N O B —CH₂—CH(CH₃)—COOH1.82 157 4Cl-phenyl CH₂O H N O B —CH₂—CH(CH₃)—COOH 1.72 159 phenyl CH₂OH N O B —CH(CH₃)—CH₂—COOH 1.87* 160 4CF₃-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 2.03* 161 4CF₃O-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH2.03* 162 4F-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.89* 1633CH₃O-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.85* 164 3F-phenyl CH₂O H NO B —CH(CH₃)—CH₂—COOH 1.89* 165 4Cl-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 1.94* 166 3CF₃O-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH1.97* 167 2F-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.92* 168 3CF₃-phenylCH₂O H N O B —CH(CH₃)—CH₂—COOH 2* 169 3Cl-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 1.95* 170 2CH₃-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH1.91* 171 4CH₃-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.92* 1722,6-diF-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.89* 173 2F,6Cl-phenylCH₂O H N O B —CH(CH₃)—CH₂—COOH 1.92* 174 2,6diCl-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 1.97* 175 2,3-diF-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 1.3* 176 3,4-diF-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH1.89* 177 2,4-diF-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.89* 1782,5-diCl-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.99* 179 3CH₃-phenylCH₂O H N O B —CH(CH₃)—CH₂—COOH 1.93* 180 3,5-diF-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 1.9* 181 2CF₃-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH1.96* 182 4-CH₃O-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 2.0* 1833,4-diCl-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.6 184 4pyridinyl CH₂O HN O B —CH(CH₃)—CH₂—COOH 1.51* 185 2F,4Cl-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 1.95* 186 2F,4CH₃-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 1.95* 187 4CN-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH1.84* 188 2,3,6-triF- CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.89* 1892,5-diF-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.89* 190 chexyl CH₂O H NO B —CH(CH₃)—CH₂—COOH 2.05* 191 2Cl,4F-phenyl CH₂O H C O H B—(CH₂)₃—COOH 1.43 192 2,3-diCl-phenyl CH₂O H C O H B —(CH₂)₃—COOH 1.48193 phenyl CH₂O H N O B —(CH₂)₃—COOH 1.24 194 2F-phenyl CH₂O H N O B—C[(CH₂)₂]—CH₂—COOH 1.87 195 4CF₃O-phenyl CH₂O 2F N O B —(CH₂)₃—COOH1.47 196 4F-phenyl CH₂O 2F N O B —(CH₂)₃—COOH 1.35 197 phenyl CH₂O 3CH₃ON O B —(CH₂)₂—COOH 1.3 198 4Cl-phenyl CH₂O 3CH₃O N O B —(CH₂)₂—COOH 1.37199 2,4diF-phenyl CH₂O 2F N O B —(CH₂)₃—COOH 1.36 200 4Me-phenyl CH₂O 2FN O B —(CH₂)₃—COOH 1.39 201 3,4diF-phenyl CH₂O 3CH₃O N O B —(CH₂)₂—COOH1.35 202 3,5diF-phenyl CH₂O 3CH₃O N O B —(CH₂)₂—COOH 1.35 2034CF3-phenyl CH₂O 3CH₃O N O B —(CH₂)₂—COOH 1.41 204 2F-phenyl CH₂O 3CH₃ON O B —(CH₂)₂—COOH 1.28 205 2,3diF-phenyl CH₂O 3CH₃O N O B —(CH₂)₂—COOH1.32 206 4CF₃-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 2.05* 207 4F-phenyl CH₂O3F N O B —(CH₂)₃—COOH 1.97* 208 3CH₃O-phenyl CH₂O 3F N O B —(CH₂)₃—COOH1.25* 209 3F-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 2.1* 210 3CF₃O-phenylCH₂O 3F N O B —(CH₂)₃—COOH 2.06* 211 4Cl-phenyl CH₂O 3F N O B—(CH₂)₃—COOH 2.03* 212 2F-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 1.96* 2133Cl-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 2* 214 4CH₃-phenyl CH₂O 3F N O B—(CH₂)₃—COOH 2.02* 215 2,6diF-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 1.94*216 2,3,6triF-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 1.98* 217 2,6diCl-phenylCH₂O 3F N O B —(CH₂)₃—COOH 2.03* 218 2,3diF-phenyl CH₂O 3F N O B—(CH₂)₃—COOH 2.03* 219 2,5diCl-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 2.06*220 3,4diF-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 2* 221 3,4diF-phenyl CH₂O3F N O B —(CH₂)₃—COOH 1.98* 222 3CH₃-phenyl CH₂O 3F N O B —(CH₂)₃—COOH2.03* 223 2CF₃-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 2.03* 224 4CH₃O-phenylCH₂O 3F N O B —(CH₂)₃—COOH 1.96* 225 3,5diF-phenyl CH₂O 3F N O B—(CH₂)₃—COOH 1.99* 226 2,4diF-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 1.98*227 3,4diCl-phenyl CH₂O 2F N O B —(CH₂)₃—COOH 1.42 228 2F,4CH₃-phenylCH₂O 3F N O B —(CH₂)₃—COOH 1.86* 229 3,4diCl-phenyl CH₂O 3F N O B—(CH₂)₃—COOH 2.07* 230 3,5diF-phenyl CH₂O 2F N O B —(CH₂)₃—COOH 1.33 2312CH₃-phenyl CH₂O 3F N O B —(CH₂)₃—COOH 1.99* 232 2Cl-phenyl CH₂O 3F N OB —(CH₂)₃—COOH 2.01* 233 4F-phenyl CH₂O 2CH₃ N O B —(CH₂)₂—COOH 1.38 2342,4diF-phenyl CH₂O 2CH₃ N O B —(CH₂)₂—COOH 1.38 235 3CF₃-phenyl CH₂O 2FN O B —(CH₂)₃—COOH 1.39 236 4CF₃O-phenyl CH₂O 3CH₃O N O B —(CH₂)₂—COOH1.44 237 2F-phenyl CH₂O 3CH₃O N O B —(CH₂)₃—COOH 1.26 238 3CF₃-phenylCH₂O 3F N O B —(CH₂)₃—COOH 2.06* 239 2F,6Cl-phenyl CH₂O 3F N O B—(CH₂)₃—COOH 1.99* 240 2,3diF-phenyl CH₂O 3CH₃O N O B —(CH₂)₃—COOH 1.26241 3CF₃O-phenyl CH₂O 2F N O B —(CH₂)₃—COOH 1.42 242 2F-phenyl CH₂O H NO B —CH₂—CF₂—COOH 2.16 243 4CH₃-phenyl CH₂O 2CH₃ N O B —(CH₂)₃—COOH 1.37244 4F-phenyl CH₂O 2CH₃ N O B —(CH₂)₃—COOH 1.33 245 2,4diF-phenyl CH₂O2CH₃ N O B —(CH₂)₃—COOH 1.33 246 3,4diF-phenyl CH₂O 3CH₃O N O B—(CH₂)₃—COOH 1.3 247 3,5diF-phenyl CH₂O 3CH₃O N O B —(CH₂)₃—COOH 1.3 2484Cl-phenyl CH₂O 3CH₃O N O B —(CH₂)₃—COOH 1.32 249 4CF₃-phenyl CH₂O 3CH₃ON O B —(CH₂)₃—COOH 1.38 250 4CF₃O-phenyl CH₂O 3CH₃O N O B —(CH₂)₃—COOH1.38 251 3CF₃-phenyl CH₂O 2CH₃ N O B —(CH₂)₃—COOH 1.4 252 3,4diCl-phenylCH₂O 2CH₃ N O B —(CH₂)₃—COOH 1.45 253 3CF₃O-phenyl CH₂O 2CH₃ N O B—(CH₂)₃—COOH 1.48 254 4Cl-phenyl CH₂O 2Cl N O B —(CH₂)₃—COOH 1.38 2553,4diF-phenyl CH₂O 2Cl N O B —(CH₂)₃—COOH 1.36 256 3,5diF-phenyl CH₂O2Cl N O B —(CH₂)₃—COOH 1.39 257 4CF₃-phenyl CH₂O 2Cl N O B —(CH₂)₃—COOH1.42 258 2F-phenyl CH₂O 3F N O B —(CH₂)₂—COOH 1.35 259 4CF3-phenyl CH₂O3F N O B —(CH₂)₂—COOH 3.02 260 3,5diF-phenyl CH₂O 3F N O B —(CH₂)₂—COOH2.98 261 2F-phenyl CH₂O 2Cl N O B —(CH₂)₃—COOH 2.94 262 3,5diF-phenylCH₂O 2CH₃ N O B —(CH₂)₃—COOH 1.66 263 2,3diF-phenyl CH₂O 2Cl N O B—(CH₂)₃—COOH 1.33 264 4CF₃O-phenyl CH₂O 2Cl N O B —(CH₂)₃—COOH 1.46 2653,5diCl-phenyl CH₂O 2Cl N O B —(CH₂)₃—COOH 1.49 266 3,5diF-Phenyl CH₂O2Cl N O B —(CH₂)₂—COOH 1.42 267 4CF₃-phenyl CH₂O 2Cl N O B —(CH₂)₂—COOH1.5 268 2F-phenyl CH₂O 2Cl N O B —(CH₂)₂—COOH 1.36 269 2,6diCH₃-phenylCH₂O 2F N O B —(CH₂)₂—COOH 1.36 271 4CF₃-phenyl CH₂O 2F N O B—CH₂—CH(CH₃)—COOH 1.56 272 2,6diCH₃-phenyl CH₂O 2CH₃ N O B —(CH₂)₂—COOH1.46 273 3,4diF-phenyl CH₂O 2CH₃O N O B —CH(CH₃)—CH₂—COOH 1.42 2744CF₃-phenyl CH₂O 2CH₃O N O B —CH(CH₃)—CH₂—COOH 1.51 275 2F-phenyl CH₂O2CH₃O N O B —CH(CH₃)—CH₂—COOH 1.37 276 3,5diF-phenyl CH₂O 2CH₃O N O B—CH(CH₃)—CH₂—COOH 1.42 277 3,4diF-phenyl CH₂O H N O B -cyclobutyl-COOH1.31 278 3,4diF-phenyl CH₂O H N O B -cyclobutyl-COOH 1.33 279 4Cl-phenylCH₂O H N O B -cyclobutyl-COOH 1.36 280 4Cl-phenyl CH₂O H N O B-cyclobutyl-COOH 1.37 281 4F-phenyl CH₂O 3Cl N O B —(CH₂)₃—COOH 2.03*282 4CF₃-phenyl CH₂O 3Cl N O B —(CH₂)₃—COOH 2.11* 283 2F-phenyl CH₂O 3ClN O B —(CH₂)₃—COOH 1.99* 284 4CF₃O-phenyl CH₂O 3Cl N O B —(CH₂)₃—COOH2.1* 285 4Cl-phenyl CH₂O 3Cl N O B —(CH₂)₃—COOH 2.07* 286 3CF₃O-phenylCH₂O 3Cl N O B —(CH₂)₃—COOH 2.14* 287 3,4diF-phenyl CH₂O 3Cl N O B—(CH₂)₃—COOH 2.03* 288 2,4diF-phenyl CH₂O 3Cl N O B —(CH₂)₃—COOH 2.02*289 3,4diCl-phenyl CH₂O 3Cl N O B —(CH₂)₃—COOH 2.16* 290 3,5diF-phenylCH₂O 3Cl N O B —(CH₂)₃—COOH 2.03* 291 2Cl-phenyl CH₂O 3Cl N O B—(CH₂)₃—COOH 2.05* 292 2F,4Cl-phenyl CH₂O 3Cl N O B —(CH₂)₃—COOH 2.06*293 3CF₃-phenyl CH₂O 3Cl N O B —(CH₂)₃—COOH 2.09* 294 2,5diF-phenyl CH₂O3Cl N O B —(CH₂)₃—COOH 2.02* 295 4CF₃-phenyl CH₂O 2F N O B—CH(CH₃)—CH₂—COOH 1.56 296 4CF₃O-phenyl CH₂O 2CH₃O N O B—CH(CH₃)—CH₂—COOH 1.54 298 3,4diF-phenyl CH₂O 3Cl N O B —(CH₂)₂—COOH1.44 299 2,3diF-phenyl CH₂O 3Cl N O B —(CH₂)₃—COOH 2.01* 301 2F-phenylCH₂O H N O B —(CH₂)₂—COOH 1.38 302 2F-phenyl CH₂O H N O B-cyclobutyl-COOH 1.29 303 2F-phenyl CH₂O H N O B -cyclobutyl-COOH 1.3304 4-fluoro-indan-2-yl O H N O B —(CH₂)₂—COOH 1.39 305 indan-2-yl O H NO B —(CH₂)₂—COOH 1.37 306 4CF₃O-phenyl CH₂O H N O B -cyclobutyl-COOH1.41 307 4CF₃O-phenyl CH₂O H N O B -cyclobutyl-COOH 1.43 308 indan-1-ylO H N O B —(CH₂)₂—COOH 1.39 309 4-fluoro-indan-1-yl O H N O B—(CH₂)₂—COOH 1.4 310 4Cl-phenyl CH₂O 3Cl N O B —(CH₂)₂—COOH 1.48 3113,4diF-phenyl CH₂O 2F N O B —CH(CH₃)—CH₂—COOH 1.45 312 4F-phenyl CH₂O HN O B -cyclobutyl-COOH 1.28 313 4F-phenyl CH₂O H N O B -cyclobutyl-COOH1.3 314 4CF₃-phenyl CH₂O H N O B -cyclobutyl-COOH 1.41 315 4CF₃-phenylCH₂O H N O B -cyclobutyl-COOH 1.42 316 3F,4Cl-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 1.52 318 2Cl,4F-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH1.5 319 2F,3Cl-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.49 3203F,5Cl-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.54 322 2,3diCl-phenylCH₂O H N O B —CH(CH₃)—CH₂—COOH 1.59 323 2Cl-phenyl CH₂O H N O B—CH(CH₃)—CH₂—COOH 1.48 324 2,4diCl-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH1.6 325 3,5diCl-phenyl CH₂O H N O B —CH(CH₃)—CH₂—COOH 1.63 3263,5diF-phenyl CH₂O H N O B -cyclobutyl-COOH (trans) 1.34 3273,5diF-phenyl CH₂O H N O B -cyclobutyl-COOH(cis) 1.34 328 3,4diCl-phenylCH₂O H N O B -cyclobutyl-COOH (trans) 1.45 329 3,4diCl-phenyl CH₂O H N OB -cyclobutyl-COOH(cis) 1.46 330 4Cl-phenyl CH₂O H N NH B—CH(CH₃)—CH₂—COOH 1.16 331 3,4diF-phenyl CH₂O H N NH B —CH(CH₃)—CH₂—COOH1.11 332 3,5diCl-phenyl CH₂O H N NH B —CH(CH₃)—CH₂—COOH 1.11 3494Cl-phenyl CH₂O H C S H B —(CH₂)₂—COOH #) 350 4CF₃-phenyl CH₂O H C S H B—(CH₂)₂—COOH 1.57 352 3,5-diCl-phenyl CH₂O H C S H B —(CH₂)₂—COOH 1.6354 3,5-diF-phenyl CH₂O H C S H B —(CH₂)₂—COOH 1.46 357 3,4-diCl-phenylCH₂O 3Cl N O B —(CH₂)₂—COOH 1.56 359 4-Cl-phenyl CH₂O 3Cl N O B—CH(CH₃)—CH₂—COOH 1.73 361 4-CF₃-phenyl O H N O B —(CH₂)₂—COOH 1.45 3632F,3Cl-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.4 364 2F,4Cl-phenyl CH₂O H N OB —(CH₂)₂—COOH 1.44 365 2Cl,4F-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.44 3663Cl,5F-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.44 367 3F,4Cl-phenyl CH₂O H NO B —(CH₂)₂—COOH 1.45 369 2,3-diCl-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.5370 2Cl-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.4 379 3,4-diCl-phenyl CH₂O HN O B —(CH₂)₂—COOH 1.5 380 3,5-diCl-phenyl CH₂O H N O B —(CH₂)₂—COOH1.53 381 2,4-diCl-phenyl CH₂O H N O B —(CH₂)₂—COOH 1.52 3903,4-diF-phenyl CH₂O 3Cl N O B —CH(CH₃)—CH₂—COOH 1.56 392 3,4-diCl-phenylCH₂O 3Cl N O B —CH(CH₃)—CH₂—COOH 1.67 393 2,3-diF-phenyl CH₂O 2Me N O B—CH(CH₃)—(CH₂)₂—COOH 1.37 394 2,3-diF-phenyl CH₂O 2Me N O B—(CH₂)₂—CH(CH₃)—COOH 1.38 395 4-Cl-phenyl CH₂O 2Me N O B—(CH₂)₂—CH(CH₃)—COOH 1.43 396 4-CF₃-phenyl CH₂O 2Me N O B—(CH₂)₂—CH(CH₃)—COOH 1.47 397 3,4-diF-phenyl CH₂O 2Me N O B—(CH₂)₂—CH(CH₃)—COOH 1.39 398 3,5-diF-phenyl CH₂O 2,6-dF N O B—(CH₂)₃—COOH 1.34 399 4CF₃-phenyl CH₂O 2,6-dF N O B —(CH₂)₃—COOH 1.42400 2,3-diF-phenyl CH₂O H N O B —(CH₂)₂—CH(CH₃)—COOH # 401 Me O H N O B—(CH₂)₂—COOH #) 402 Me O H N O B —(CH₂)₃—COOH # 406 4Cl-phenyl CH₂O2,3diF N O B —(CH₂)₃—COOH 1.37 407 3,5-diF-phenyl CH₂O 2,3diF N O B—(CH₂)₃—COOH 1.35 408 4Cl-phenyl CH₂O 2,3diF N O B —CH(CH₃)—CH₂—COOH1.53 409 3,5-diF-phenyl CH₂O 2,3diF N O B —CH(CH₃)—CH₂—COOH 1.48 4104Cl-phenyl CH₂O 2,3diF N O B trans cyclobutyl-COOH 1.41 4113,5-diF-phenyl CH₂O 2,3diF N O B cis-cyclobutyl-COOH 1.41 4123,5-diF-phenyl CH₂O 2,3diF N O B trans cyclobutyl-COOH 1.36 4133,5-diF-phenyl CH₂O 2,3diF N O B cis-cyclobutyl-COOH 1.35 4143,4-diF-phenyl CH₂O 2Me N O B cis-cyclobutyl-COOH # 415 3,4-diF-phenylCH₂O 2Me N O B trans cyclobutyl-COOH # 416 2,3-diF-phenyl CH₂O 3F N O B—CH(CH₃)—CH₂—COOH # 418 2,3-diF-phenyl CH₂O 3F N O B cis-cyclobutyl-COOH# 419 3,5-diF-phenyl CH₂O 3Me N O B —(CH₂)₃—COOH 1.38 421 3,5-diF-phenylCH₂O 3Me N O B —CH(CH₃)—CH₂—COOH 1.63 422 4CF₃-phenyl CH2S H N O B—(CH₂)₃—COOH 1.12 423 3,4-diF-phenyl CH2S H N O B —(CH₂)₃—COOH 1.09 4242,3-diF-phenyl CH₂O 3F N O B trans cyclobutyl-COOH # 425 2,3-diF-phenylCH₂O H N O B —CH(CH₃)—CH₂—COOH chiral2 1.11 426 2,3-diF-phenyl CH₂O H NO B —CH(CH₃)—CH₂—COOH chiral1 1.2 427 3,5-diF-phenyl CH₂O 3Me N O Btrans cyclobutyl-COOH 1.37 429 2,3-diF-phenyl CH₂O 3Me N O B transcyclobutyl-COOH 1.35 431 3,5-diF-phenyl CH₂O 2Me N O B —CH(CH₃)—CH₂—COOH1.5 434 2,3-diF-phenyl CH₂O 2Me N O B —CH(CH₃)—CH₂—COOH 1.47 4372,3-diF-phenyl CH₂O 2Me N O B —CH₂—CH(CH₃)—CH₂—COOH 1.42 4392,3-diF-phenyl CH₂O 3Me N O B —CHCH₃—CH₂—COOH 1.49 441 4-Cl-phenyl CH₂SH N O B —(CH₂)₃—COOH 1.38 442 2,3-diF-phenyl CH₂S H N O B —(CH₂)₃—COOH1.33 443 3,5-diF-phenyl CH₂S H N O B —(CH₂)₃—COOH 1.34 4443,4-diCl-phenyl CH₂S H N O B —(CH₂)₃—COOH 1.44 445 4-Cl-phenyl CH₂O H NS B —(CH₂)₃—COOH 1.36 446 3,5-diF-phenyl CH₂O H N S B —(CH₂)₃—COOH 1.33447 4-Cl-phenyl CH₂O H N S B —CH(CH₃)—CH₂—COOH 1.53 448 3,5-diF-phenylCH₂O H N S B —CH(CH₃)—CH₂—COOH 1.48 451 3,5-diF-phenyl C═C H N O B—(CH₂)₃—COOH 1.39 HC═CH 452 3,5-diF-phenyl (CH₂)₂ H N O B —(CH₂)₃—COOH1.36 455 phenyl cyclopropyl 3F N O B trans cyclobutyl-COOH 1.36 456phenyl cyclopropyl 3F N O B cis cyclobutyl-COOH 1.39 457 phenylcyclopropyl 3F N O B —CH(CH₃)—CH₂—COOH 1.55 459 phenyl cyclopropyl 3F NO B trans cyclobutyl-COOH 1.36 460 phenyl cyclopropyl 3F N O B ciscyclobutyl-COOH 1.39 461 phenyl cyclopropyl 3F N O B —CH(CH₃)—CH₂—COOH1.55 463 3,5-diF-phenyl CH₂O H N O B —CH₂COOH 1.51 464 3,5-diF-phenylCH₂O H N O B —CH(CH₃)—COOH 1.53 465 3,5-diF-phenyl CH₂O H N O B1,3-cyclopentyl-COOH 1.27 *= determined with LC-MS method B # = NMR inaccordance with proposed structure

§6. Pharmacological Tests & Data

In Vitro Functional Activity (Agonism) on Human S1P5 Receptors

The CHO-human-S1P5-Aeqorin assay was bought from Euroscreen, Brussels(Euroscreen, Technical dossier, Human Lysophospholid S1P5 (Edg8)receptor, DNA clone and CHO AequoScreen™ recombinant cell-line, catalogn°: ES-593-A, September 2006). Human-S1P5-Aequorin cells expressmitochondrial targeted apo-Aequorin. Cells have to be loaded withcoelanterazine, in order to reconstitute active Aequorin. After bindingof agonists to the human S1P5 receptor the intracellular calciumconcentration increases and binding of calcium to theapo-Aequorin/coelenterazine complex leads to an oxidation reaction ofcoelenterazine, which results in the production of apo-Aequorin,coelenteramide, CO₂ and light (□_(max) 469 nm). This luminescentresponse is dependent on the agonist concentration. Luminescence ismeasured using the MicroBeta Jet (Perkin Elmer). Agonistic effects ofcompounds are expressed as pEC₅₀. Compounds were tested at a 10 pointshalf log concentration range, and 3 independent experiments wereperformed in single point's measurements.

In Vitro Functional Activity (Agonism) on Human S1P3 Receptors

The CHO-human-S1P3-Aeqorin assay (CHO/Ga16/AEQ/h-S1P3) was establishedat Solvay Pharmaceuticals. The plasmid DNA coding for the S1P3 receptor(accession number in GenBank NM_005226 was purchased from UMR cDNAresource Centre (Rolla, Mo.). The pcDNA3.1/hS1P3 construct carrying themitochondrially targeted apo-Aeqorin and Ga16 protein was transfected inCHO K1 cell-line. Human-S1P3-Aequorin cells express mitochondrialtargeted apo-Aequorin. Cells have to be loaded with coelanterazine, inorder to reconstitute active Aequorin. After binding of agonists to thehuman S1P3 receptor the intracellular calcium concentration increasesand binding of calcium to the apo-Aequorin/coelenterazine complex leadsto an oxidation reaction of coelenterazine, which results in theproduction of apo-Aequorin, coelenteramide, CO₂ and light (□_(max) 469nm). This luminescent response is dependent on the agonistconcentration. Luminescence is measured using the MicroBeta Jet (PerkinElmer). Agonistic effects of compounds are expressed as pEC₅₀. Compoundswere tested at a 10 points half log concentration range, and 3independent experiments were performed in single point's measurements.

In Vitro Functional Activity (Agonism) on Human S1P1 Receptors (MethodA)

The CHO-K1-human-S1P1-Aeqorin assay was bought from Euroscreen Fast,Brussels (Euroscreen, Technical dossier, Human S1P1 (Edg1) receptor, DNAclone and CHO-K1 AequoScreen™ recombinant cell-line, catalog n°:FAST-0197L, February 2010). Human-S1P1-Aequorin cells expressmitochondrial targeted apo-Aequorin. Cells have to be loaded withcoelanterazine, in order to reconstitute active Aequorin. After bindingof agonists to the human S1P1 receptor the intracellular calciumconcentration increases and binding of calcium to theapo-Aequorin/coelenterazine complex leads to an oxidation reaction ofcoelenterazine, which results in the production of apo-Aequorin,coelenteramide, CO₂ and light (□_(max) 469 nm). This luminescentresponse is dependent on the agonist concentration. Luminescence ismeasured using the MicroBeta Jet (Perkin Elmer). Agonistic effects ofcompounds are expressed as pEC₅₀. Compounds were tested at a 10 pointshalf log concentration range, and 2 independent experiments wereperformed in single point's measurements.

In Vitro Functional Activity (Agonism) on Human S1P1 Receptors (MethodB)

The CHO-K1-Human S1P1-c-AMP assay was performed at Euroscreenfast,Brussels (Euroscreen, Human S1P1 coupling G_(i/0), (Edg1) receptor,catalog n°: FAST-0197C, December 2009).

Recombinant CHO-K1 cells expressing human S1P1, grown to mid-log Phasein culture media without antibiotics, detached, centrifuged andre-suspended. For agonist testing cells are mixed with compound andForskolin and incubated at room temperature. Cells are lyses and cAMPconcentration are estimated, according to the manufacturerspecification, With the HTRF kit from CIS-BIO International (catn°62AM2PEB).

Agonistic effects of compounds are expressed as a percentage of theactivity of the reference compound at its EC₁₀₀ concentration, EC₅₀ iscalculated and results are reported as pEC₅₀. Compounds were tested at a10 points half log concentration range duplicated in 1 experiment.

Pharmacological Data (Receptor Agonism) for Selected Compounds:

S1P5 Compound pEC₅₀ S1P1^(A)pEC₅₀ S1P1^(B)pEC₅₀ S1P3 pEC₅₀  33 7.8 7.05.5  35 8.3 6.6 5.3  47 8.0 <5.5 <5  53 7.9 <4.5 <5  57 8.0 <5.5 <5  738.2 8.0 6.3  76 8.1 6.6 <5  77 8.4 7.5 6.1  85 8.6 <5.5 6.3  89 8.2 5.9<5.0 146 7.8 <5.5 <5.0 156 8.4 6.2 5.5 157 8.1 6.2 5.3 175 8.3 <5.5 5.8211 8.3 6.1 <5.0 227 8.5 6.0 <6.0 271 8.0 6.2 5.4 277 (trans) 8.5 5.2<5.0 278 (cis) 7.4 <5 <5 283 7.7 <4.5 <5 306 (trans) 8.1 <5 <5.0 307(cis) 7.3 <5 <5.0 S1P1^(A): determined using method A S1P1^(B):determined using method B

In Vivo Therapeutic Model; T-Maze

Age-related memory deficits occur in humans and rodents. Spontaneousalternation is the innate tendency of rodents to alternate free choicesin a T-maze over a series of successive runs. This sequential procedurerelies on working memory and is sensitive to various pharmacologicalmanipulations affecting memory processes (Aging and the physiology ofspatial memory. Barnes C. A. Neurobiol. Aging 1988:563-8; Dember W N,Fowler H. Spontaneous alternation behavior. Psychol. Bull. 1958, 55(6):412-427; Gerlai R. A new continuous alternation task in T-mazedetects hippocampal dysfunction in mice. A strain comparison and lesionstudy. Behav Brain Res 1998 95 (1):91-101).

For this study, male C57BL/6J mice of 2 months or 12 months old wereused in the spontaneous alternation task in the T-maze. In short, micewere subjected to 1 session containing 15 trials, consisting of 1“forced-choice” trial, followed by 14 “free-choice” trials. The animalwas considered as entering one of the arms of the maze when all fourpaws are placed within this arm. A session is terminated and the animalis removed from the maze as soon as 14 free-choice trials have beenperformed or 15 min have elapsed, whatever event occurs first. Thepercentage of alternation over the 14 free-choice trials was determinedfor each mouse and was used as an index of working memory performance. Acompound of the invention was administrated p.o. for 21 days prior theT-maze assay and on the day of the T-maze at t=−30 min. It was foundthat compounds of the invention at doses ranging from of 0.01-15mg/kg/day reverse the age-related cognitive decline in the 12-month oldC57BL6J mice with up to 100%. Thus, treated 12 month old mice wereidentical in their performance as 2 months old vehicle-treated mice.(See FIG. 1)

CONCLUSION

compounds of the present invention have a positive effect on age-relatedcognitive decline.

The invention claimed is:
 1. A compound of the formula (I)

or a pharmaceutically acceptable salt, solvate, or hydrate thereof, oran N-oxide of any of the foregoing, wherein R1 is selected from thegroup consisting of: a cyano group, a group independently selected froma (2-4C)alkenyl group, a (2-4C)alkynyl group, and a (1-4C)alkyl group,wherein each group is optionally substituted with a substituentindependently selected from CN and at least one halogen atom, a groupindependently selected from a (3-6C)cycloalkyl group, a(4-6C)cycloalkenyl group, and a (8-10C)bicyclic group, wherein eachgroup is optionally substituted with a substituent independentlyselected from a halogen atom and a (1-4C)alkyl group optionallysubstituted with at least one halogen atom, a group independentlyselected from a phenyl group, a biphenyl group, and a naphthyl group,wherein each group is optionally substituted with at least onesubstituent independently selected from halogen, cyano, (1-4C)alkyloptionally substituted with at least one halogen atom, (1-4C)alkoxyoptionally substituted with at least one halogen atom, amino,dimethylamino, and (3-6C)cycloalkyl optionally substituted with a phenylgroup wherein the phenyl group is optionally substituted with asubstituent independently selected from (1-4C)alkyl and a halogen atom,and a group independently selected from a phenyl group, a biphenylgroup, and a naphthyl group, wherein each group is optionallysubstituted with at least one substituent independently selected fromhalogen, cyano, (1-4C)alkyl optionally substituted with at least onehalogen atom, (1-4C)alkoxy optionally substituted with at least onehalogen atom, amino, dimethylamino, and (3-6C)cycloalkyl optionallysubstituted with a phenyl group wherein the phenyl group is optionallysubstituted with a substituent independently selected from (1-4C)alkyland a halogen atom, and a phenyl group substituted with a group selectedfrom the group consisting of a phenoxy group, a benzyl group, abenzyloxy group, a phenylethyl group, and a monocyclic heterocyclegroup, wherein each group is optionally substituted with (1-4C)alkyl, Zis a —W—(C_(n)-alkylene)-T-group wherein W is attached to R1 andselected from the group consisting of a bond, —O—, —CO—, —S—, —SO—,—SO₂—, —NH—, —CH═CH—, —C(CF₃)═CH—, —C≡C—, —CH₂—O—, —O—CO—, —CO—O—,—CO—NH—, NH—CO— and a trans-cyclopropylene; n is an integer from 0 to10; and T is attached to the phenylene/pyridyl moiety and selected fromthe group consisting of a bond, —O—, —S—, —SO—, —SO₂—, —NH—, —CO—, —C═C——CH═CH—, —C≡C—, and a trans-cyclopropylene; R2 is selected from thegroup consisting of H and at least one substituent independentlyselected from cyano, halogen, (1-4C)alkyl optionally substituted with atleast one halogen atom, and (1-4C)alkoxy optionally substituted with atleast one or more halogen atom; ring structure A optionally contains anitrogen atom; X is selected from the group consisting of C and N;wherein if X is C, R3 is selected from H and (1-4C)alkyl, and if X is N,R3 is not present; Y is selected from the group consisting of NH, O andS O; structure Q is selected from the group consisting of a 5-, 6- and7-membered cyclic amine; and R4 is selected from a (1-4C)alkylene-R5group wherein at least one carbon atom in the alkylene group mayindependently be substituted with a substituent selected from at leastone halogen atom and a (CH₂)₂ to form a cyclopropyl moiety, or a groupindependently selected from (3-6C)cycloalkylene-R5,—CH₂-(3-6C)cycloalkylene-R5, (3-6C)cycloalkylene-CH₂—R5 and —CO—CH₂—R5,wherein R5 is selected from —OH, —PO₃H₂, —OPO₃H₂, —COOH, —COO(1-4C)alkyland tetrazol-5yl tetrazol-5-yl.
 2. The compound of claim 1, wherein R1is selected from a group independently selected from a (3-6C)cycloalkylgroup and a (8-10C)bicyclic group wherein the group is optionallysubstituted with a halogen atom, (1-4C)alkyl, or a phenyl group whereinthe phenyl group is optionally substituted with at least one substituentindependently selected from the group consisting of a halogen atom,cyano, (1-4C)alkyl, (1-4C)alkoxy, a trifluoromethyl, and atrifluoromethoxy; W is selected from the group consisting of a bond,—O—, —CO—, —S—, —SO—, —SO₂—, —NH—, —CH═CH—, —C≡C—, and atrans-cyclopropylene; n is an integer from 0 to 4; and R2 is selectedfrom the group consisting of H, at least one substituent independentlyselected from a halogen atom, (1-4C)alkyl optionally substituted with atleast one fluoro and (1-4C)alkoxy optionally substituted with at leastone fluoro atom.
 3. The compound of claim 1, wherein the compound hasthe structure (Ia)

wherein R1, R2, R3, R4, R5, Q, T, W, X, Y, Z, and n are as defined inclaim
 1. 4. The compound of claim 1, wherein the compound has thestructure (Ib)

wherein R1, R2, R3, R4, R5, Q, T, W, X, Y, Z, and n are as defined inclaim
 1. 5. The compound of claim 1, wherein Y is O.
 6. The compound ofclaim 1, wherein R4 is selected from the group consisting of—(CH₂)₂—COOH, —(CH₂)₃—COOH, —CH₂—CHCH₃—COOH, —CH₂—C(CH₃)₂—COOH,—CHCH₃—CH₂—COOH, —CH₂—CF₂—COOH, and 1,3-cyclobutylene-COOH.
 7. Thecompound of claim 1, wherein R1 is a phenyl group optionally substitutedwith at least one substituent independently selected from the groupconsisting of halogen, cyano, (1-4C)alkyl optionally substituted with atleast one halogen atom, (1-4C)alkoxy optionally substituted with atleast one halogen atom, amino, dimethylamino, and (3-6C)cycloalkyloptionally substituted with a phenyl group wherein the phenyl group isoptionally substituted with a substituent independently selected from(1-4C)alkyl and a halogen atom.
 8. The compound of claim 7, wherein R1is a phenyl group optionally substituted with at least one substituentindependently selected from a halogen atom, cyano, (1-4C)alkyl,(1-4C)alkoxy, a trifluoromethyl, and a trifluoromethoxy.
 9. The compoundof claim 1, wherein Z is —CH₂O—.
 10. The compound of claim 1, wherein Xis N.
 11. The compound of claim 1, wherein the compound is selectedfrom:3-{2-[4-(2-Fluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-propionicacid,3-{2-[4-(4-Chloro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-2-methyl-propionicacid,3-{2-[4-Benzyloxy-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-butyricacid,4-{2-[4-(2-Fluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-butyricacid,4-{2-[4-(2-Fluoro-benzyloxy)-2-fluoro-phenyl]-6,7-dihydro-4H-furo[3,2-c]pyridine-5-yl}-butyricacid,3-{2-[4-(Benzyloxy)-phenyl)]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-propionicacid,4-{2-[4-(2,3-Difluoro-benzyloxy)-phenyl)]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid,4-{2[4-Benzyloxy-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid,4-{2[4-(4-Trifluoromethyl-benzyloxy)-2-fluoro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid,4-{2[4-(2-Fluoro-benzyloxy)-2-methyl-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid,4-{2[4-(3,4-Dichloro-benzyloxy)-2-fluoro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid,4-{2[4-(2-Fluoro-benzyloxy)-3-chloro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid,4-{2[4-(4-Chloro-benzyloxy)-3-fluoro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid,3[2-(4-Benzyloxy-phenyl)-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl]-2-methyl-propionicacid,3-[2-(4-Benzyloxy-phenyl)-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl]-2-methyl-propionicacid,3-{2[4-(4-Trifluoromethyl-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-2-methyl-propionicacid,3-{2[4-(4-Chloro-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-2-methyl-propionicacid,3-{2[4-(2,3-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-butyricacid,3-{2[4-(4-Trifluoromethyl-benzyloxy)-2-fluoro-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-2-methyl-propionicacid, Cis and trans3-{2[4-(4-Trifluoromethoxybenzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-cyclobutanecarboxylic acid, Cis and trans3-{2[4-(3,4-Difluorobenzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-cyclobutanecarboxylic acid,3[2-(4-(2-Fluoro-benzyloxy)-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-yl]-propionicacid,4-{2-[4-(3,5-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-thiazolo-[4,5c]-pyridin-5-yl}-butyricacid,2-{2-[4-(3,5-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-aceticacid,2-{2-[4-(3,5-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-H-oxazolo[4,5-c]pyridine-5-yl}-propionicacid,3-{2-[4-(3,5-Difluoro-benzyloxy)-phenyl]-6,7-dihydro-4H-oxazolo[4,5-c]-pyridin-5-yl}-cyclopentanecarboxylic acid,4-{2-[4-(2,3-Difluoro-benzyloxy)-2-methyl-phenyl]-6,7-dihydro-4H-oxazolo[4,5c]-pyridin-5-yl}-pentanoicacid,4-{2-[4-(2,3-Difluoro-benzyloxy)-2-methyl-phenyl]-6,7-dihydro-4H-oxazolo[4,5-c]-pyridin-5-yl}-2-methyl-butyricacid,4-{2[4-(2,3-Difluoro-benzyloxy)-2-methyl-phenyl]-6,7-dihydro-4H-oxazolo-[4,5c]-pyridin-5-yl}-3-methyl-butyricacid,3-{2-[4-(2-phenyl-cyclopropyl)-3-fluoro-phenyl]-6,7-dihydro-4H-oxazolo-[4,5-c]-pyridin-5-yl}-cyclobutanecarboxylic acid,4-(2-{4-(2-(3,5-Difluoro-phenyl)-vinyl]-phenyl}-6,7-dihydro-4H-oxazolo-[4,5c]-pyridin-5-yl)-butyricacid, and4-(2-{4-[2-(3,5-Difluoro-phenyl)-ethyl]-phenyl}-6,7-dihydro-4H-oxazolo[4,5c]pyridin-5-yl)-butyricacid, or a pharmaceutically acceptable salt, solvateor solvate orhydrate thereof, or an N-oxide of any of the foregoing.
 12. Apharmaceutical composition comprising the compound of claim 1 and atleast one pharmaceutically acceptable excipient.
 13. A compound selectedfrom the group consisting of:3-(2-(4-((2-fluorobenzyl)oxy)phenyl)-6,7-dihydrooxazolo[4,5-c]pyridin-5(4H)-yl)propanoicacid;3-(2-(4-((4-chlorobenzyl)oxy)phenyl)-6,7-dihydrooxazolo[4,5-c]pyridin-5(4H)-yl)-2-methylpropanoicacid;2-methyl-3-(2-(4-((4-(trifluoromethyl)benzyl)oxy)phenyl)-6,7-dihydrooxazolo[4,5-c]pyridin-5(4H)-yl)propanoicacid; Trans3-(2-(4-((3,4-difluorobenzyl)oxy)phenyl)-6,7-dihydrooxazolo[4,5-c]pyridin-5(4H)-yl)cyclobutanecarboxylicacid;3-(2-(4-((4-cyanobenzyl)oxy)phenyl)-6,7-dihydrooxazolo[4,5-c]pyridin-5(4H)-yl)butanoicacid; and3-(2-(4-((2,3-difluorobenzyl)oxy)phenyl)-6,7-dihydrooxazolo[4,5-c]pyridin-5(4H)-yl)butanoicacid, or a pharmaceutically acceptable salt, a solvate or hydratethereof, or an N-oxide of any of the foregoing.
 14. A compoundcomprising:

or a pharmaceutically acceptable salt, a solvate or hydrate thereof, oran N-oxide of any of the foregoing.
 15. A compound comprising:

or a pharmaceutically acceptable salt, a solvate or hydrate thereof, oran N-oxide of any of the foregoing.
 16. A compound comprising:

or a pharmaceutically acceptable salt, a solvate or hydrate thereof, oran N-oxide of any of the foregoing.
 17. A compound comprising:

or a pharmaceutically acceptable salt, a solvate or hydrate thereof, oran N-oxide of any of the foregoing.
 18. A compound comprising:

or a pharmaceutically acceptable salt, a solvate or hydrate thereof, oran N-oxide of any of the foregoing.
 19. A compound comprising

or a pharmaceutically acceptable salt, a solvate or hydrate thereof, oran N-oxide of any of the foregoing.
 20. A compound comprising the plus(+) enantiomer of

or a pharmaceutically acceptable salt, a solvate or hydrate thereof, oran N-oxide of any of the foregoing.
 21. A compound comprising the minus(−) enantiomer of

or a pharmaceutically acceptable salt, a solvate or hydrate thereof, oran N-oxide of any of the foregoing.
 22. A pharmaceutical compositioncomprising a compound of claim 11, and at least one pharmaceuticallyacceptable excipient.
 23. A pharmaceutical composition comprising acompound of claim 13, and at least one pharmaceutically acceptableexcipient.
 24. A pharmaceutical composition comprising a compound ofclaim 14, and at least one pharmaceutically acceptable excipient.
 25. Apharmaceutical composition comprising a compound of claim 15, and atleast one pharmaceutically acceptable excipient.
 26. A pharmaceuticalcomposition comprising a compound of claim 16, and at least onepharmaceutically acceptable excipient.
 27. A pharmaceutical compositioncomprising a compound of claim 17, and at least one pharmaceuticallyacceptable excipient.
 28. A pharmaceutical composition comprising acompound of claim 18, and at least one pharmaceutically acceptableexcipient.
 29. A pharmaceutical composition comprising a compound ofclaim 19, and at least one pharmaceutically acceptable excipient.
 30. Apharmaceutical composition comprising a compound of claim 20, and atleast one pharmaceutically acceptable excipient.
 31. A pharmaceuticalcomposition comprising a compound of claim 21 20, and at least onepharmaceutically acceptable excipient.
 32. A compound of formula:

or a pharmaceutically acceptable salt thereof.
 33. The compound of claim32, or a pharmaceutically acceptable salt thereof, which is the cisisomer.
 34. The compound of claim 32, or a pharmaceutically acceptablesalt thereof, which is the trans isomer.
 35. A pharmaceuticalcomposition comprising the compound of claim 32, or a pharmaceuticallyacceptable salt thereof, and at least one pharmaceutically acceptableexcipient.
 36. A pharmaceutical composition comprising the compound ofclaim 33, or a pharmaceutically acceptable salt thereof, and at leastone pharmaceutically acceptable excipient.
 37. A pharmaceuticalcomposition comprising the compound of claim 34, or a pharmaceuticallyacceptable salt thereof, and at least one pharmaceutically acceptableexcipient.
 38. A compound of formula:

or a pharmaceutically acceptable salt thereof, wherein R4 is-cyclobutyl-COOH.
 39. A pharmaceutical composition comprising thecompound of claim 38, or a pharmaceutically acceptable salt thereof, andat least one pharmaceutically acceptable excipient.